1 /* Handle parameterized types (templates) for GNU C++.
2 Copyright (C) 1992, 1993, 1994, 1995, 1996, 1997, 1998, 1999, 2000,
3 2001, 2002, 2003, 2004, 2005, 2007, 2008, 2009, 2010, 2011
4 Free Software Foundation, Inc.
5 Written by Ken Raeburn (raeburn@cygnus.com) while at Watchmaker Computing.
6 Rewritten by Jason Merrill (jason@cygnus.com).
8 This file is part of GCC.
10 GCC is free software; you can redistribute it and/or modify
11 it under the terms of the GNU General Public License as published by
12 the Free Software Foundation; either version 3, or (at your option)
15 GCC is distributed in the hope that it will be useful,
16 but WITHOUT ANY WARRANTY; without even the implied warranty of
17 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
18 GNU General Public License for more details.
20 You should have received a copy of the GNU General Public License
21 along with GCC; see the file COPYING3. If not see
22 <http://www.gnu.org/licenses/>. */
24 /* Known bugs or deficiencies include:
26 all methods must be provided in header files; can't use a source
27 file that contains only the method templates and "just win". */
31 #include "coretypes.h"
35 #include "pointer-set.h"
38 #include "c-family/c-common.h"
39 #include "c-family/c-objc.h"
40 #include "cp-objcp-common.h"
41 #include "tree-inline.h"
46 #include "tree-iterator.h"
49 /* The type of functions taking a tree, and some additional data, and
51 typedef int (*tree_fn_t) (tree, void*);
53 /* The PENDING_TEMPLATES is a TREE_LIST of templates whose
54 instantiations have been deferred, either because their definitions
55 were not yet available, or because we were putting off doing the work. */
56 struct GTY (()) pending_template {
57 struct pending_template *next;
58 struct tinst_level *tinst;
61 static GTY(()) struct pending_template *pending_templates;
62 static GTY(()) struct pending_template *last_pending_template;
64 int processing_template_parmlist;
65 static int template_header_count;
67 static GTY(()) tree saved_trees;
68 static VEC(int,heap) *inline_parm_levels;
70 static GTY(()) struct tinst_level *current_tinst_level;
72 static GTY(()) tree saved_access_scope;
74 /* Live only within one (recursive) call to tsubst_expr. We use
75 this to pass the statement expression node from the STMT_EXPR
76 to the EXPR_STMT that is its result. */
77 static tree cur_stmt_expr;
79 /* A map from local variable declarations in the body of the template
80 presently being instantiated to the corresponding instantiated
82 static htab_t local_specializations;
84 typedef struct GTY(()) spec_entry
91 static GTY ((param_is (spec_entry)))
92 htab_t decl_specializations;
94 static GTY ((param_is (spec_entry)))
95 htab_t type_specializations;
97 /* Contains canonical template parameter types. The vector is indexed by
98 the TEMPLATE_TYPE_IDX of the template parameter. Each element is a
99 TREE_LIST, whose TREE_VALUEs contain the canonical template
100 parameters of various types and levels. */
101 static GTY(()) VEC(tree,gc) *canonical_template_parms;
103 #define UNIFY_ALLOW_NONE 0
104 #define UNIFY_ALLOW_MORE_CV_QUAL 1
105 #define UNIFY_ALLOW_LESS_CV_QUAL 2
106 #define UNIFY_ALLOW_DERIVED 4
107 #define UNIFY_ALLOW_INTEGER 8
108 #define UNIFY_ALLOW_OUTER_LEVEL 16
109 #define UNIFY_ALLOW_OUTER_MORE_CV_QUAL 32
110 #define UNIFY_ALLOW_OUTER_LESS_CV_QUAL 64
112 static void push_access_scope (tree);
113 static void pop_access_scope (tree);
114 static bool resolve_overloaded_unification (tree, tree, tree, tree,
115 unification_kind_t, int);
116 static int try_one_overload (tree, tree, tree, tree, tree,
117 unification_kind_t, int, bool);
118 static int unify (tree, tree, tree, tree, int);
119 static void add_pending_template (tree);
120 static tree reopen_tinst_level (struct tinst_level *);
121 static tree tsubst_initializer_list (tree, tree);
122 static tree get_class_bindings (tree, tree, tree);
123 static tree coerce_template_parms (tree, tree, tree, tsubst_flags_t,
125 static void tsubst_enum (tree, tree, tree);
126 static tree add_to_template_args (tree, tree);
127 static tree add_outermost_template_args (tree, tree);
128 static bool check_instantiated_args (tree, tree, tsubst_flags_t);
129 static int maybe_adjust_types_for_deduction (unification_kind_t, tree*, tree*,
131 static int type_unification_real (tree, tree, tree, const tree *,
132 unsigned int, int, unification_kind_t, int);
133 static void note_template_header (int);
134 static tree convert_nontype_argument_function (tree, tree);
135 static tree convert_nontype_argument (tree, tree, tsubst_flags_t);
136 static tree convert_template_argument (tree, tree, tree,
137 tsubst_flags_t, int, tree);
138 static int for_each_template_parm (tree, tree_fn_t, void*,
139 struct pointer_set_t*, bool);
140 static tree expand_template_argument_pack (tree);
141 static tree build_template_parm_index (int, int, int, int, tree, tree);
142 static bool inline_needs_template_parms (tree);
143 static void push_inline_template_parms_recursive (tree, int);
144 static tree retrieve_local_specialization (tree);
145 static void register_local_specialization (tree, tree);
146 static hashval_t hash_specialization (const void *p);
147 static tree reduce_template_parm_level (tree, tree, int, tree, tsubst_flags_t);
148 static int mark_template_parm (tree, void *);
149 static int template_parm_this_level_p (tree, void *);
150 static tree tsubst_friend_function (tree, tree);
151 static tree tsubst_friend_class (tree, tree);
152 static int can_complete_type_without_circularity (tree);
153 static tree get_bindings (tree, tree, tree, bool);
154 static int template_decl_level (tree);
155 static int check_cv_quals_for_unify (int, tree, tree);
156 static void template_parm_level_and_index (tree, int*, int*);
157 static int unify_pack_expansion (tree, tree, tree, tree, int, bool, bool);
158 static tree tsubst_template_arg (tree, tree, tsubst_flags_t, tree);
159 static tree tsubst_template_args (tree, tree, tsubst_flags_t, tree);
160 static tree tsubst_template_parms (tree, tree, tsubst_flags_t);
161 static void regenerate_decl_from_template (tree, tree);
162 static tree most_specialized_class (tree, tree, tsubst_flags_t);
163 static tree tsubst_aggr_type (tree, tree, tsubst_flags_t, tree, int);
164 static tree tsubst_arg_types (tree, tree, tsubst_flags_t, tree);
165 static tree tsubst_function_type (tree, tree, tsubst_flags_t, tree);
166 static bool check_specialization_scope (void);
167 static tree process_partial_specialization (tree);
168 static void set_current_access_from_decl (tree);
169 static tree get_template_base (tree, tree, tree, tree);
170 static tree try_class_unification (tree, tree, tree, tree);
171 static int coerce_template_template_parms (tree, tree, tsubst_flags_t,
173 static bool template_template_parm_bindings_ok_p (tree, tree);
174 static int template_args_equal (tree, tree);
175 static void tsubst_default_arguments (tree);
176 static tree for_each_template_parm_r (tree *, int *, void *);
177 static tree copy_default_args_to_explicit_spec_1 (tree, tree);
178 static void copy_default_args_to_explicit_spec (tree);
179 static int invalid_nontype_parm_type_p (tree, tsubst_flags_t);
180 static int eq_local_specializations (const void *, const void *);
181 static bool dependent_template_arg_p (tree);
182 static bool any_template_arguments_need_structural_equality_p (tree);
183 static bool dependent_type_p_r (tree);
184 static tree tsubst_expr (tree, tree, tsubst_flags_t, tree, bool);
185 static tree tsubst_copy (tree, tree, tsubst_flags_t, tree);
186 static tree tsubst_pack_expansion (tree, tree, tsubst_flags_t, tree);
187 static tree tsubst_decl (tree, tree, tsubst_flags_t);
188 static void perform_typedefs_access_check (tree tmpl, tree targs);
189 static void append_type_to_template_for_access_check_1 (tree, tree, tree,
191 static tree listify (tree);
192 static tree listify_autos (tree, tree);
193 static tree template_parm_to_arg (tree t);
194 static tree current_template_args (void);
195 static tree fixup_template_type_parm_type (tree, int);
196 static tree fixup_template_parm_index (tree, tree, int);
197 static tree tsubst_template_parm (tree, tree, tsubst_flags_t);
199 /* Make the current scope suitable for access checking when we are
200 processing T. T can be FUNCTION_DECL for instantiated function
201 template, or VAR_DECL for static member variable (need by
202 instantiate_decl). */
205 push_access_scope (tree t)
207 gcc_assert (TREE_CODE (t) == FUNCTION_DECL
208 || TREE_CODE (t) == VAR_DECL);
210 if (DECL_FRIEND_CONTEXT (t))
211 push_nested_class (DECL_FRIEND_CONTEXT (t));
212 else if (DECL_CLASS_SCOPE_P (t))
213 push_nested_class (DECL_CONTEXT (t));
215 push_to_top_level ();
217 if (TREE_CODE (t) == FUNCTION_DECL)
219 saved_access_scope = tree_cons
220 (NULL_TREE, current_function_decl, saved_access_scope);
221 current_function_decl = t;
225 /* Restore the scope set up by push_access_scope. T is the node we
229 pop_access_scope (tree t)
231 if (TREE_CODE (t) == FUNCTION_DECL)
233 current_function_decl = TREE_VALUE (saved_access_scope);
234 saved_access_scope = TREE_CHAIN (saved_access_scope);
237 if (DECL_FRIEND_CONTEXT (t) || DECL_CLASS_SCOPE_P (t))
240 pop_from_top_level ();
243 /* Do any processing required when DECL (a member template
244 declaration) is finished. Returns the TEMPLATE_DECL corresponding
245 to DECL, unless it is a specialization, in which case the DECL
246 itself is returned. */
249 finish_member_template_decl (tree decl)
251 if (decl == error_mark_node)
252 return error_mark_node;
254 gcc_assert (DECL_P (decl));
256 if (TREE_CODE (decl) == TYPE_DECL)
260 type = TREE_TYPE (decl);
261 if (type == error_mark_node)
262 return error_mark_node;
263 if (MAYBE_CLASS_TYPE_P (type)
264 && CLASSTYPE_TEMPLATE_INFO (type)
265 && !CLASSTYPE_TEMPLATE_SPECIALIZATION (type))
267 tree tmpl = CLASSTYPE_TI_TEMPLATE (type);
268 check_member_template (tmpl);
273 else if (TREE_CODE (decl) == FIELD_DECL)
274 error ("data member %qD cannot be a member template", decl);
275 else if (DECL_TEMPLATE_INFO (decl))
277 if (!DECL_TEMPLATE_SPECIALIZATION (decl))
279 check_member_template (DECL_TI_TEMPLATE (decl));
280 return DECL_TI_TEMPLATE (decl);
286 error ("invalid member template declaration %qD", decl);
288 return error_mark_node;
291 /* Create a template info node. */
294 build_template_info (tree template_decl, tree template_args)
296 tree result = make_node (TEMPLATE_INFO);
297 TI_TEMPLATE (result) = template_decl;
298 TI_ARGS (result) = template_args;
302 /* Return the template info node corresponding to T, whatever T is. */
305 get_template_info (const_tree t)
307 tree tinfo = NULL_TREE;
309 if (!t || t == error_mark_node)
312 if (DECL_P (t) && DECL_LANG_SPECIFIC (t))
313 tinfo = DECL_TEMPLATE_INFO (t);
315 if (!tinfo && DECL_IMPLICIT_TYPEDEF_P (t))
318 if (TAGGED_TYPE_P (t))
319 tinfo = TYPE_TEMPLATE_INFO (t);
320 else if (TREE_CODE (t) == BOUND_TEMPLATE_TEMPLATE_PARM)
321 tinfo = TEMPLATE_TEMPLATE_PARM_TEMPLATE_INFO (t);
326 /* Returns the template nesting level of the indicated class TYPE.
336 A<T>::B<U> has depth two, while A<T> has depth one.
337 Both A<T>::B<int> and A<int>::B<U> have depth one, if
338 they are instantiations, not specializations.
340 This function is guaranteed to return 0 if passed NULL_TREE so
341 that, for example, `template_class_depth (current_class_type)' is
345 template_class_depth (tree type)
350 type && TREE_CODE (type) != NAMESPACE_DECL;
351 type = (TREE_CODE (type) == FUNCTION_DECL)
352 ? CP_DECL_CONTEXT (type) : CP_TYPE_CONTEXT (type))
354 tree tinfo = get_template_info (type);
356 if (tinfo && PRIMARY_TEMPLATE_P (TI_TEMPLATE (tinfo))
357 && uses_template_parms (INNERMOST_TEMPLATE_ARGS (TI_ARGS (tinfo))))
364 /* Subroutine of maybe_begin_member_template_processing.
365 Returns true if processing DECL needs us to push template parms. */
368 inline_needs_template_parms (tree decl)
370 if (! DECL_TEMPLATE_INFO (decl))
373 return (TMPL_PARMS_DEPTH (DECL_TEMPLATE_PARMS (most_general_template (decl)))
374 > (processing_template_decl + DECL_TEMPLATE_SPECIALIZATION (decl)));
377 /* Subroutine of maybe_begin_member_template_processing.
378 Push the template parms in PARMS, starting from LEVELS steps into the
379 chain, and ending at the beginning, since template parms are listed
383 push_inline_template_parms_recursive (tree parmlist, int levels)
385 tree parms = TREE_VALUE (parmlist);
389 push_inline_template_parms_recursive (TREE_CHAIN (parmlist), levels - 1);
391 ++processing_template_decl;
392 current_template_parms
393 = tree_cons (size_int (processing_template_decl),
394 parms, current_template_parms);
395 TEMPLATE_PARMS_FOR_INLINE (current_template_parms) = 1;
397 begin_scope (TREE_VEC_LENGTH (parms) ? sk_template_parms : sk_template_spec,
399 for (i = 0; i < TREE_VEC_LENGTH (parms); ++i)
401 tree parm = TREE_VALUE (TREE_VEC_ELT (parms, i));
403 if (parm == error_mark_node)
406 gcc_assert (DECL_P (parm));
408 switch (TREE_CODE (parm))
417 /* Make a CONST_DECL as is done in process_template_parm.
418 It is ugly that we recreate this here; the original
419 version built in process_template_parm is no longer
421 tree decl = build_decl (DECL_SOURCE_LOCATION (parm),
422 CONST_DECL, DECL_NAME (parm),
424 DECL_ARTIFICIAL (decl) = 1;
425 TREE_CONSTANT (decl) = 1;
426 TREE_READONLY (decl) = 1;
427 DECL_INITIAL (decl) = DECL_INITIAL (parm);
428 SET_DECL_TEMPLATE_PARM_P (decl);
439 /* Restore the template parameter context for a member template or
440 a friend template defined in a class definition. */
443 maybe_begin_member_template_processing (tree decl)
448 if (inline_needs_template_parms (decl))
450 parms = DECL_TEMPLATE_PARMS (most_general_template (decl));
451 levels = TMPL_PARMS_DEPTH (parms) - processing_template_decl;
453 if (DECL_TEMPLATE_SPECIALIZATION (decl))
456 parms = TREE_CHAIN (parms);
459 push_inline_template_parms_recursive (parms, levels);
462 /* Remember how many levels of template parameters we pushed so that
463 we can pop them later. */
464 VEC_safe_push (int, heap, inline_parm_levels, levels);
467 /* Undo the effects of maybe_begin_member_template_processing. */
470 maybe_end_member_template_processing (void)
475 if (VEC_length (int, inline_parm_levels) == 0)
478 last = VEC_pop (int, inline_parm_levels);
479 for (i = 0; i < last; ++i)
481 --processing_template_decl;
482 current_template_parms = TREE_CHAIN (current_template_parms);
487 /* Return a new template argument vector which contains all of ARGS,
488 but has as its innermost set of arguments the EXTRA_ARGS. */
491 add_to_template_args (tree args, tree extra_args)
498 if (args == NULL_TREE || extra_args == error_mark_node)
501 extra_depth = TMPL_ARGS_DEPTH (extra_args);
502 new_args = make_tree_vec (TMPL_ARGS_DEPTH (args) + extra_depth);
504 for (i = 1; i <= TMPL_ARGS_DEPTH (args); ++i)
505 SET_TMPL_ARGS_LEVEL (new_args, i, TMPL_ARGS_LEVEL (args, i));
507 for (j = 1; j <= extra_depth; ++j, ++i)
508 SET_TMPL_ARGS_LEVEL (new_args, i, TMPL_ARGS_LEVEL (extra_args, j));
513 /* Like add_to_template_args, but only the outermost ARGS are added to
514 the EXTRA_ARGS. In particular, all but TMPL_ARGS_DEPTH
515 (EXTRA_ARGS) levels are added. This function is used to combine
516 the template arguments from a partial instantiation with the
517 template arguments used to attain the full instantiation from the
518 partial instantiation. */
521 add_outermost_template_args (tree args, tree extra_args)
525 /* If there are more levels of EXTRA_ARGS than there are ARGS,
526 something very fishy is going on. */
527 gcc_assert (TMPL_ARGS_DEPTH (args) >= TMPL_ARGS_DEPTH (extra_args));
529 /* If *all* the new arguments will be the EXTRA_ARGS, just return
531 if (TMPL_ARGS_DEPTH (args) == TMPL_ARGS_DEPTH (extra_args))
534 /* For the moment, we make ARGS look like it contains fewer levels. */
535 TREE_VEC_LENGTH (args) -= TMPL_ARGS_DEPTH (extra_args);
537 new_args = add_to_template_args (args, extra_args);
539 /* Now, we restore ARGS to its full dimensions. */
540 TREE_VEC_LENGTH (args) += TMPL_ARGS_DEPTH (extra_args);
545 /* Return the N levels of innermost template arguments from the ARGS. */
548 get_innermost_template_args (tree args, int n)
556 /* If N is 1, just return the innermost set of template arguments. */
558 return TMPL_ARGS_LEVEL (args, TMPL_ARGS_DEPTH (args));
560 /* If we're not removing anything, just return the arguments we were
562 extra_levels = TMPL_ARGS_DEPTH (args) - n;
563 gcc_assert (extra_levels >= 0);
564 if (extra_levels == 0)
567 /* Make a new set of arguments, not containing the outer arguments. */
568 new_args = make_tree_vec (n);
569 for (i = 1; i <= n; ++i)
570 SET_TMPL_ARGS_LEVEL (new_args, i,
571 TMPL_ARGS_LEVEL (args, i + extra_levels));
576 /* The inverse of get_innermost_template_args: Return all but the innermost
577 EXTRA_LEVELS levels of template arguments from the ARGS. */
580 strip_innermost_template_args (tree args, int extra_levels)
583 int n = TMPL_ARGS_DEPTH (args) - extra_levels;
588 /* If N is 1, just return the outermost set of template arguments. */
590 return TMPL_ARGS_LEVEL (args, 1);
592 /* If we're not removing anything, just return the arguments we were
594 gcc_assert (extra_levels >= 0);
595 if (extra_levels == 0)
598 /* Make a new set of arguments, not containing the inner arguments. */
599 new_args = make_tree_vec (n);
600 for (i = 1; i <= n; ++i)
601 SET_TMPL_ARGS_LEVEL (new_args, i,
602 TMPL_ARGS_LEVEL (args, i));
607 /* We've got a template header coming up; push to a new level for storing
611 begin_template_parm_list (void)
613 /* We use a non-tag-transparent scope here, which causes pushtag to
614 put tags in this scope, rather than in the enclosing class or
615 namespace scope. This is the right thing, since we want
616 TEMPLATE_DECLS, and not TYPE_DECLS for template classes. For a
617 global template class, push_template_decl handles putting the
618 TEMPLATE_DECL into top-level scope. For a nested template class,
621 template <class T> struct S1 {
622 template <class T> struct S2 {};
625 pushtag contains special code to call pushdecl_with_scope on the
626 TEMPLATE_DECL for S2. */
627 begin_scope (sk_template_parms, NULL);
628 ++processing_template_decl;
629 ++processing_template_parmlist;
630 note_template_header (0);
633 /* This routine is called when a specialization is declared. If it is
634 invalid to declare a specialization here, an error is reported and
635 false is returned, otherwise this routine will return true. */
638 check_specialization_scope (void)
640 tree scope = current_scope ();
644 An explicit specialization shall be declared in the namespace of
645 which the template is a member, or, for member templates, in the
646 namespace of which the enclosing class or enclosing class
647 template is a member. An explicit specialization of a member
648 function, member class or static data member of a class template
649 shall be declared in the namespace of which the class template
651 if (scope && TREE_CODE (scope) != NAMESPACE_DECL)
653 error ("explicit specialization in non-namespace scope %qD", scope);
659 In an explicit specialization declaration for a member of a class
660 template or a member template that appears in namespace scope,
661 the member template and some of its enclosing class templates may
662 remain unspecialized, except that the declaration shall not
663 explicitly specialize a class member template if its enclosing
664 class templates are not explicitly specialized as well. */
665 if (current_template_parms)
667 error ("enclosing class templates are not explicitly specialized");
674 /* We've just seen template <>. */
677 begin_specialization (void)
679 begin_scope (sk_template_spec, NULL);
680 note_template_header (1);
681 return check_specialization_scope ();
684 /* Called at then end of processing a declaration preceded by
688 end_specialization (void)
691 reset_specialization ();
694 /* Any template <>'s that we have seen thus far are not referring to a
695 function specialization. */
698 reset_specialization (void)
700 processing_specialization = 0;
701 template_header_count = 0;
704 /* We've just seen a template header. If SPECIALIZATION is nonzero,
705 it was of the form template <>. */
708 note_template_header (int specialization)
710 processing_specialization = specialization;
711 template_header_count++;
714 /* We're beginning an explicit instantiation. */
717 begin_explicit_instantiation (void)
719 gcc_assert (!processing_explicit_instantiation);
720 processing_explicit_instantiation = true;
725 end_explicit_instantiation (void)
727 gcc_assert (processing_explicit_instantiation);
728 processing_explicit_instantiation = false;
731 /* An explicit specialization or partial specialization TMPL is being
732 declared. Check that the namespace in which the specialization is
733 occurring is permissible. Returns false iff it is invalid to
734 specialize TMPL in the current namespace. */
737 check_specialization_namespace (tree tmpl)
739 tree tpl_ns = decl_namespace_context (tmpl);
743 An explicit specialization shall be declared in the namespace of
744 which the template is a member, or, for member templates, in the
745 namespace of which the enclosing class or enclosing class
746 template is a member. An explicit specialization of a member
747 function, member class or static data member of a class template
748 shall be declared in the namespace of which the class template is
750 if (current_scope() != DECL_CONTEXT (tmpl)
751 && !at_namespace_scope_p ())
753 error ("specialization of %qD must appear at namespace scope", tmpl);
756 if (is_associated_namespace (current_namespace, tpl_ns))
757 /* Same or super-using namespace. */
761 permerror (input_location, "specialization of %qD in different namespace", tmpl);
762 permerror (input_location, " from definition of %q+#D", tmpl);
767 /* SPEC is an explicit instantiation. Check that it is valid to
768 perform this explicit instantiation in the current namespace. */
771 check_explicit_instantiation_namespace (tree spec)
775 /* DR 275: An explicit instantiation shall appear in an enclosing
776 namespace of its template. */
777 ns = decl_namespace_context (spec);
778 if (!is_ancestor (current_namespace, ns))
779 permerror (input_location, "explicit instantiation of %qD in namespace %qD "
780 "(which does not enclose namespace %qD)",
781 spec, current_namespace, ns);
784 /* The TYPE is being declared. If it is a template type, that means it
785 is a partial specialization. Do appropriate error-checking. */
788 maybe_process_partial_specialization (tree type)
792 if (type == error_mark_node)
793 return error_mark_node;
795 if (TREE_CODE (type) == BOUND_TEMPLATE_TEMPLATE_PARM)
797 error ("name of class shadows template template parameter %qD",
799 return error_mark_node;
802 context = TYPE_CONTEXT (type);
804 if (CLASS_TYPE_P (type) && CLASSTYPE_USE_TEMPLATE (type))
806 /* This is for ordinary explicit specialization and partial
807 specialization of a template class such as:
809 template <> class C<int>;
813 template <class T> class C<T*>;
815 Make sure that `C<int>' and `C<T*>' are implicit instantiations. */
817 if (CLASSTYPE_IMPLICIT_INSTANTIATION (type)
818 && !COMPLETE_TYPE_P (type))
820 check_specialization_namespace (CLASSTYPE_TI_TEMPLATE (type));
821 SET_CLASSTYPE_TEMPLATE_SPECIALIZATION (type);
822 if (processing_template_decl)
824 if (push_template_decl (TYPE_MAIN_DECL (type))
826 return error_mark_node;
829 else if (CLASSTYPE_TEMPLATE_INSTANTIATION (type))
830 error ("specialization of %qT after instantiation", type);
832 else if (CLASS_TYPE_P (type)
833 && !CLASSTYPE_USE_TEMPLATE (type)
834 && CLASSTYPE_TEMPLATE_INFO (type)
835 && context && CLASS_TYPE_P (context)
836 && CLASSTYPE_TEMPLATE_INFO (context))
838 /* This is for an explicit specialization of member class
839 template according to [temp.expl.spec/18]:
841 template <> template <class U> class C<int>::D;
843 The context `C<int>' must be an implicit instantiation.
844 Otherwise this is just a member class template declared
847 template <> class C<int> { template <class U> class D; };
848 template <> template <class U> class C<int>::D;
850 In the first case, `C<int>::D' is a specialization of `C<T>::D'
851 while in the second case, `C<int>::D' is a primary template
852 and `C<T>::D' may not exist. */
854 if (CLASSTYPE_IMPLICIT_INSTANTIATION (context)
855 && !COMPLETE_TYPE_P (type))
858 tree tmpl = CLASSTYPE_TI_TEMPLATE (type);
860 if (current_namespace
861 != decl_namespace_context (tmpl))
863 permerror (input_location, "specializing %q#T in different namespace", type);
864 permerror (input_location, " from definition of %q+#D", tmpl);
867 /* Check for invalid specialization after instantiation:
869 template <> template <> class C<int>::D<int>;
870 template <> template <class U> class C<int>::D; */
872 for (t = DECL_TEMPLATE_INSTANTIATIONS (tmpl);
873 t; t = TREE_CHAIN (t))
875 tree inst = TREE_VALUE (t);
876 if (CLASSTYPE_TEMPLATE_SPECIALIZATION (inst))
878 /* We already have a full specialization of this partial
879 instantiation. Reassign it to the new member
880 specialization template. */
884 elt.tmpl = most_general_template (tmpl);
885 elt.args = CLASSTYPE_TI_ARGS (inst);
888 htab_remove_elt (type_specializations, &elt);
891 elt.args = INNERMOST_TEMPLATE_ARGS (elt.args);
893 slot = (spec_entry **)
894 htab_find_slot (type_specializations, &elt, INSERT);
895 *slot = ggc_alloc_spec_entry ();
898 else if (COMPLETE_OR_OPEN_TYPE_P (inst))
899 /* But if we've had an implicit instantiation, that's a
900 problem ([temp.expl.spec]/6). */
901 error ("specialization %qT after instantiation %qT",
905 /* Mark TYPE as a specialization. And as a result, we only
906 have one level of template argument for the innermost
908 SET_CLASSTYPE_TEMPLATE_SPECIALIZATION (type);
909 CLASSTYPE_TI_ARGS (type)
910 = INNERMOST_TEMPLATE_ARGS (CLASSTYPE_TI_ARGS (type));
913 else if (processing_specialization)
915 /* Someday C++0x may allow for enum template specialization. */
916 if (cxx_dialect > cxx98 && TREE_CODE (type) == ENUMERAL_TYPE
917 && CLASS_TYPE_P (context) && CLASSTYPE_USE_TEMPLATE (context))
918 pedwarn (input_location, OPT_pedantic, "template specialization "
919 "of %qD not allowed by ISO C++", type);
922 error ("explicit specialization of non-template %qT", type);
923 return error_mark_node;
930 /* Returns nonzero if we can optimize the retrieval of specializations
931 for TMPL, a TEMPLATE_DECL. In particular, for such a template, we
932 do not use DECL_TEMPLATE_SPECIALIZATIONS at all. */
935 optimize_specialization_lookup_p (tree tmpl)
937 return (DECL_FUNCTION_TEMPLATE_P (tmpl)
938 && DECL_CLASS_SCOPE_P (tmpl)
939 /* DECL_CLASS_SCOPE_P holds of T::f even if T is a template
941 && CLASS_TYPE_P (DECL_CONTEXT (tmpl))
942 /* The optimized lookup depends on the fact that the
943 template arguments for the member function template apply
944 purely to the containing class, which is not true if the
945 containing class is an explicit or partial
947 && !CLASSTYPE_TEMPLATE_SPECIALIZATION (DECL_CONTEXT (tmpl))
948 && !DECL_MEMBER_TEMPLATE_P (tmpl)
949 && !DECL_CONV_FN_P (tmpl)
950 /* It is possible to have a template that is not a member
951 template and is not a member of a template class:
953 template <typename T>
954 struct S { friend A::f(); };
956 Here, the friend function is a template, but the context does
957 not have template information. The optimized lookup relies
958 on having ARGS be the template arguments for both the class
959 and the function template. */
960 && !DECL_FRIEND_P (DECL_TEMPLATE_RESULT (tmpl)));
963 /* Retrieve the specialization (in the sense of [temp.spec] - a
964 specialization is either an instantiation or an explicit
965 specialization) of TMPL for the given template ARGS. If there is
966 no such specialization, return NULL_TREE. The ARGS are a vector of
967 arguments, or a vector of vectors of arguments, in the case of
968 templates with more than one level of parameters.
970 If TMPL is a type template and CLASS_SPECIALIZATIONS_P is true,
971 then we search for a partial specialization matching ARGS. This
972 parameter is ignored if TMPL is not a class template. */
975 retrieve_specialization (tree tmpl, tree args, hashval_t hash)
977 if (args == error_mark_node)
980 gcc_assert (TREE_CODE (tmpl) == TEMPLATE_DECL);
982 /* There should be as many levels of arguments as there are
983 levels of parameters. */
984 gcc_assert (TMPL_ARGS_DEPTH (args)
985 == TMPL_PARMS_DEPTH (DECL_TEMPLATE_PARMS (tmpl)));
987 if (optimize_specialization_lookup_p (tmpl))
990 tree class_specialization;
991 VEC(tree,gc) *methods;
995 /* The template arguments actually apply to the containing
996 class. Find the class specialization with those
998 class_template = CLASSTYPE_TI_TEMPLATE (DECL_CONTEXT (tmpl));
1000 = retrieve_specialization (class_template, args, 0);
1001 if (!class_specialization)
1003 /* Now, find the appropriate entry in the CLASSTYPE_METHOD_VEC
1004 for the specialization. */
1005 idx = class_method_index_for_fn (class_specialization, tmpl);
1008 /* Iterate through the methods with the indicated name, looking
1009 for the one that has an instance of TMPL. */
1010 methods = CLASSTYPE_METHOD_VEC (class_specialization);
1011 for (fns = VEC_index (tree, methods, idx); fns; fns = OVL_NEXT (fns))
1013 tree fn = OVL_CURRENT (fns);
1014 if (DECL_TEMPLATE_INFO (fn) && DECL_TI_TEMPLATE (fn) == tmpl
1015 /* using-declarations can add base methods to the method vec,
1016 and we don't want those here. */
1017 && DECL_CONTEXT (fn) == class_specialization)
1026 htab_t specializations;
1030 elt.spec = NULL_TREE;
1032 if (DECL_CLASS_TEMPLATE_P (tmpl))
1033 specializations = type_specializations;
1035 specializations = decl_specializations;
1038 hash = hash_specialization (&elt);
1039 found = (spec_entry *) htab_find_with_hash (specializations, &elt, hash);
1047 /* Like retrieve_specialization, but for local declarations. */
1050 retrieve_local_specialization (tree tmpl)
1054 if (local_specializations == NULL)
1057 spec = (tree) htab_find_with_hash (local_specializations, tmpl,
1058 htab_hash_pointer (tmpl));
1059 return spec ? TREE_PURPOSE (spec) : NULL_TREE;
1062 /* Returns nonzero iff DECL is a specialization of TMPL. */
1065 is_specialization_of (tree decl, tree tmpl)
1069 if (TREE_CODE (decl) == FUNCTION_DECL)
1073 t = DECL_TEMPLATE_INFO (t) ? DECL_TI_TEMPLATE (t) : NULL_TREE)
1079 gcc_assert (TREE_CODE (decl) == TYPE_DECL);
1081 for (t = TREE_TYPE (decl);
1083 t = CLASSTYPE_USE_TEMPLATE (t)
1084 ? TREE_TYPE (CLASSTYPE_TI_TEMPLATE (t)) : NULL_TREE)
1085 if (same_type_ignoring_top_level_qualifiers_p (t, TREE_TYPE (tmpl)))
1092 /* Returns nonzero iff DECL is a specialization of friend declaration
1093 FRIEND_DECL according to [temp.friend]. */
1096 is_specialization_of_friend (tree decl, tree friend_decl)
1098 bool need_template = true;
1101 gcc_assert (TREE_CODE (decl) == FUNCTION_DECL
1102 || TREE_CODE (decl) == TYPE_DECL);
1104 /* For [temp.friend/6] when FRIEND_DECL is an ordinary member function
1105 of a template class, we want to check if DECL is a specialization
1107 if (TREE_CODE (friend_decl) == FUNCTION_DECL
1108 && DECL_TEMPLATE_INFO (friend_decl)
1109 && !DECL_USE_TEMPLATE (friend_decl))
1111 /* We want a TEMPLATE_DECL for `is_specialization_of'. */
1112 friend_decl = DECL_TI_TEMPLATE (friend_decl);
1113 need_template = false;
1115 else if (TREE_CODE (friend_decl) == TEMPLATE_DECL
1116 && !PRIMARY_TEMPLATE_P (friend_decl))
1117 need_template = false;
1119 /* There is nothing to do if this is not a template friend. */
1120 if (TREE_CODE (friend_decl) != TEMPLATE_DECL)
1123 if (is_specialization_of (decl, friend_decl))
1127 A member of a class template may be declared to be a friend of a
1128 non-template class. In this case, the corresponding member of
1129 every specialization of the class template is a friend of the
1130 class granting friendship.
1132 For example, given a template friend declaration
1134 template <class T> friend void A<T>::f();
1136 the member function below is considered a friend
1138 template <> struct A<int> {
1142 For this type of template friend, TEMPLATE_DEPTH below will be
1143 nonzero. To determine if DECL is a friend of FRIEND, we first
1144 check if the enclosing class is a specialization of another. */
1146 template_depth = template_class_depth (CP_DECL_CONTEXT (friend_decl));
1148 && DECL_CLASS_SCOPE_P (decl)
1149 && is_specialization_of (TYPE_NAME (DECL_CONTEXT (decl)),
1150 CLASSTYPE_TI_TEMPLATE (DECL_CONTEXT (friend_decl))))
1152 /* Next, we check the members themselves. In order to handle
1153 a few tricky cases, such as when FRIEND_DECL's are
1155 template <class T> friend void A<T>::g(T t);
1156 template <class T> template <T t> friend void A<T>::h();
1160 void A<int>::g(int);
1161 template <int> void A<int>::h();
1163 we need to figure out ARGS, the template arguments from
1164 the context of DECL. This is required for template substitution
1165 of `T' in the function parameter of `g' and template parameter
1166 of `h' in the above examples. Here ARGS corresponds to `int'. */
1168 tree context = DECL_CONTEXT (decl);
1169 tree args = NULL_TREE;
1170 int current_depth = 0;
1172 while (current_depth < template_depth)
1174 if (CLASSTYPE_TEMPLATE_INFO (context))
1176 if (current_depth == 0)
1177 args = TYPE_TI_ARGS (context);
1179 args = add_to_template_args (TYPE_TI_ARGS (context), args);
1182 context = TYPE_CONTEXT (context);
1185 if (TREE_CODE (decl) == FUNCTION_DECL)
1190 tree friend_args_type;
1191 tree decl_args_type;
1193 /* Make sure that both DECL and FRIEND_DECL are templates or
1195 is_template = DECL_TEMPLATE_INFO (decl)
1196 && PRIMARY_TEMPLATE_P (DECL_TI_TEMPLATE (decl));
1197 if (need_template ^ is_template)
1199 else if (is_template)
1201 /* If both are templates, check template parameter list. */
1203 = tsubst_template_parms (DECL_TEMPLATE_PARMS (friend_decl),
1205 if (!comp_template_parms
1206 (DECL_TEMPLATE_PARMS (DECL_TI_TEMPLATE (decl)),
1210 decl_type = TREE_TYPE (DECL_TI_TEMPLATE (decl));
1213 decl_type = TREE_TYPE (decl);
1215 friend_type = tsubst_function_type (TREE_TYPE (friend_decl), args,
1216 tf_none, NULL_TREE);
1217 if (friend_type == error_mark_node)
1220 /* Check if return types match. */
1221 if (!same_type_p (TREE_TYPE (decl_type), TREE_TYPE (friend_type)))
1224 /* Check if function parameter types match, ignoring the
1225 `this' parameter. */
1226 friend_args_type = TYPE_ARG_TYPES (friend_type);
1227 decl_args_type = TYPE_ARG_TYPES (decl_type);
1228 if (DECL_NONSTATIC_MEMBER_FUNCTION_P (friend_decl))
1229 friend_args_type = TREE_CHAIN (friend_args_type);
1230 if (DECL_NONSTATIC_MEMBER_FUNCTION_P (decl))
1231 decl_args_type = TREE_CHAIN (decl_args_type);
1233 return compparms (decl_args_type, friend_args_type);
1237 /* DECL is a TYPE_DECL */
1239 tree decl_type = TREE_TYPE (decl);
1241 /* Make sure that both DECL and FRIEND_DECL are templates or
1244 = CLASSTYPE_TEMPLATE_INFO (decl_type)
1245 && PRIMARY_TEMPLATE_P (CLASSTYPE_TI_TEMPLATE (decl_type));
1247 if (need_template ^ is_template)
1249 else if (is_template)
1252 /* If both are templates, check the name of the two
1253 TEMPLATE_DECL's first because is_friend didn't. */
1254 if (DECL_NAME (CLASSTYPE_TI_TEMPLATE (decl_type))
1255 != DECL_NAME (friend_decl))
1258 /* Now check template parameter list. */
1260 = tsubst_template_parms (DECL_TEMPLATE_PARMS (friend_decl),
1262 return comp_template_parms
1263 (DECL_TEMPLATE_PARMS (CLASSTYPE_TI_TEMPLATE (decl_type)),
1267 return (DECL_NAME (decl)
1268 == DECL_NAME (friend_decl));
1274 /* Register the specialization SPEC as a specialization of TMPL with
1275 the indicated ARGS. IS_FRIEND indicates whether the specialization
1276 is actually just a friend declaration. Returns SPEC, or an
1277 equivalent prior declaration, if available. */
1280 register_specialization (tree spec, tree tmpl, tree args, bool is_friend,
1284 spec_entry **slot = NULL;
1287 gcc_assert (TREE_CODE (tmpl) == TEMPLATE_DECL && DECL_P (spec));
1289 if (TREE_CODE (spec) == FUNCTION_DECL
1290 && uses_template_parms (DECL_TI_ARGS (spec)))
1291 /* This is the FUNCTION_DECL for a partial instantiation. Don't
1292 register it; we want the corresponding TEMPLATE_DECL instead.
1293 We use `uses_template_parms (DECL_TI_ARGS (spec))' rather than
1294 the more obvious `uses_template_parms (spec)' to avoid problems
1295 with default function arguments. In particular, given
1296 something like this:
1298 template <class T> void f(T t1, T t = T())
1300 the default argument expression is not substituted for in an
1301 instantiation unless and until it is actually needed. */
1304 if (optimize_specialization_lookup_p (tmpl))
1305 /* We don't put these specializations in the hash table, but we might
1306 want to give an error about a mismatch. */
1307 fn = retrieve_specialization (tmpl, args, 0);
1315 hash = hash_specialization (&elt);
1317 slot = (spec_entry **)
1318 htab_find_slot_with_hash (decl_specializations, &elt, hash, INSERT);
1325 /* We can sometimes try to re-register a specialization that we've
1326 already got. In particular, regenerate_decl_from_template calls
1327 duplicate_decls which will update the specialization list. But,
1328 we'll still get called again here anyhow. It's more convenient
1329 to simply allow this than to try to prevent it. */
1332 else if (fn && DECL_TEMPLATE_SPECIALIZATION (spec))
1334 if (DECL_TEMPLATE_INSTANTIATION (fn))
1336 if (DECL_ODR_USED (fn)
1337 || DECL_EXPLICIT_INSTANTIATION (fn))
1339 error ("specialization of %qD after instantiation",
1341 return error_mark_node;
1346 /* This situation should occur only if the first
1347 specialization is an implicit instantiation, the
1348 second is an explicit specialization, and the
1349 implicit instantiation has not yet been used. That
1350 situation can occur if we have implicitly
1351 instantiated a member function and then specialized
1354 We can also wind up here if a friend declaration that
1355 looked like an instantiation turns out to be a
1358 template <class T> void foo(T);
1359 class S { friend void foo<>(int) };
1360 template <> void foo(int);
1362 We transform the existing DECL in place so that any
1363 pointers to it become pointers to the updated
1366 If there was a definition for the template, but not
1367 for the specialization, we want this to look as if
1368 there were no definition, and vice versa. */
1369 DECL_INITIAL (fn) = NULL_TREE;
1370 duplicate_decls (spec, fn, is_friend);
1371 /* The call to duplicate_decls will have applied
1374 An explicit specialization of a function template
1375 is inline only if it is explicitly declared to be,
1376 and independently of whether its function template
1379 to the primary function; now copy the inline bits to
1380 the various clones. */
1381 FOR_EACH_CLONE (clone, fn)
1383 DECL_DECLARED_INLINE_P (clone)
1384 = DECL_DECLARED_INLINE_P (fn);
1385 DECL_SOURCE_LOCATION (clone)
1386 = DECL_SOURCE_LOCATION (fn);
1388 check_specialization_namespace (fn);
1393 else if (DECL_TEMPLATE_SPECIALIZATION (fn))
1395 if (!duplicate_decls (spec, fn, is_friend) && DECL_INITIAL (spec))
1396 /* Dup decl failed, but this is a new definition. Set the
1397 line number so any errors match this new
1399 DECL_SOURCE_LOCATION (fn) = DECL_SOURCE_LOCATION (spec);
1405 return duplicate_decls (spec, fn, is_friend);
1407 /* A specialization must be declared in the same namespace as the
1408 template it is specializing. */
1409 if (DECL_TEMPLATE_SPECIALIZATION (spec)
1410 && !check_specialization_namespace (tmpl))
1411 DECL_CONTEXT (spec) = DECL_CONTEXT (tmpl);
1413 if (!optimize_specialization_lookup_p (tmpl))
1415 gcc_assert (tmpl && args && spec);
1416 *slot = ggc_alloc_spec_entry ();
1418 if (TREE_CODE (spec) == FUNCTION_DECL && DECL_NAMESPACE_SCOPE_P (spec)
1419 && PRIMARY_TEMPLATE_P (tmpl)
1420 && DECL_SAVED_TREE (DECL_TEMPLATE_RESULT (tmpl)) == NULL_TREE)
1421 /* TMPL is a forward declaration of a template function; keep a list
1422 of all specializations in case we need to reassign them to a friend
1423 template later in tsubst_friend_function. */
1424 DECL_TEMPLATE_INSTANTIATIONS (tmpl)
1425 = tree_cons (args, spec, DECL_TEMPLATE_INSTANTIATIONS (tmpl));
1431 /* Returns true iff two spec_entry nodes are equivalent. Only compares the
1432 TMPL and ARGS members, ignores SPEC. */
1435 eq_specializations (const void *p1, const void *p2)
1437 const spec_entry *e1 = (const spec_entry *)p1;
1438 const spec_entry *e2 = (const spec_entry *)p2;
1440 return (e1->tmpl == e2->tmpl
1441 && comp_template_args (e1->args, e2->args));
1444 /* Returns a hash for a template TMPL and template arguments ARGS. */
1447 hash_tmpl_and_args (tree tmpl, tree args)
1449 hashval_t val = DECL_UID (tmpl);
1450 return iterative_hash_template_arg (args, val);
1453 /* Returns a hash for a spec_entry node based on the TMPL and ARGS members,
1457 hash_specialization (const void *p)
1459 const spec_entry *e = (const spec_entry *)p;
1460 return hash_tmpl_and_args (e->tmpl, e->args);
1463 /* Recursively calculate a hash value for a template argument ARG, for use
1464 in the hash tables of template specializations. */
1467 iterative_hash_template_arg (tree arg, hashval_t val)
1469 unsigned HOST_WIDE_INT i;
1470 enum tree_code code;
1473 if (arg == NULL_TREE)
1474 return iterative_hash_object (arg, val);
1479 if (TREE_CODE (arg) == ARGUMENT_PACK_SELECT)
1480 /* We can get one of these when re-hashing a previous entry in the middle
1481 of substituting into a pack expansion. Just look through it. */
1482 arg = ARGUMENT_PACK_SELECT_FROM_PACK (arg);
1484 code = TREE_CODE (arg);
1485 tclass = TREE_CODE_CLASS (code);
1487 val = iterative_hash_object (code, val);
1494 case IDENTIFIER_NODE:
1495 return iterative_hash_object (IDENTIFIER_HASH_VALUE (arg), val);
1499 int i, len = TREE_VEC_LENGTH (arg);
1500 for (i = 0; i < len; ++i)
1501 val = iterative_hash_template_arg (TREE_VEC_ELT (arg, i), val);
1505 case TYPE_PACK_EXPANSION:
1506 case EXPR_PACK_EXPANSION:
1507 return iterative_hash_template_arg (PACK_EXPANSION_PATTERN (arg), val);
1509 case TYPE_ARGUMENT_PACK:
1510 case NONTYPE_ARGUMENT_PACK:
1511 return iterative_hash_template_arg (ARGUMENT_PACK_ARGS (arg), val);
1514 for (; arg; arg = TREE_CHAIN (arg))
1515 val = iterative_hash_template_arg (TREE_VALUE (arg), val);
1519 for (; arg; arg = OVL_CHAIN (arg))
1520 val = iterative_hash_template_arg (OVL_FUNCTION (arg), val);
1526 FOR_EACH_CONSTRUCTOR_ELT (CONSTRUCTOR_ELTS (arg), i, field, value)
1528 val = iterative_hash_template_arg (field, val);
1529 val = iterative_hash_template_arg (value, val);
1535 if (!DECL_ARTIFICIAL (arg))
1536 val = iterative_hash_object (DECL_PARM_INDEX (arg), val);
1537 return iterative_hash_template_arg (TREE_TYPE (arg), val);
1540 return iterative_hash_template_arg (TARGET_EXPR_INITIAL (arg), val);
1543 val = iterative_hash_template_arg (PTRMEM_CST_CLASS (arg), val);
1544 return iterative_hash_template_arg (PTRMEM_CST_MEMBER (arg), val);
1546 case TEMPLATE_PARM_INDEX:
1547 val = iterative_hash_template_arg
1548 (TREE_TYPE (TEMPLATE_PARM_DECL (arg)), val);
1549 val = iterative_hash_object (TEMPLATE_PARM_LEVEL (arg), val);
1550 return iterative_hash_object (TEMPLATE_PARM_IDX (arg), val);
1553 val = iterative_hash_object (TRAIT_EXPR_KIND (arg), val);
1554 val = iterative_hash_template_arg (TRAIT_EXPR_TYPE1 (arg), val);
1555 return iterative_hash_template_arg (TRAIT_EXPR_TYPE2 (arg), val);
1558 val = iterative_hash_template_arg (BINFO_TYPE (BASELINK_BINFO (arg)),
1560 return iterative_hash_template_arg (DECL_NAME (get_first_fn (arg)),
1564 val = iterative_hash_template_arg (TREE_OPERAND (arg, 0), val);
1565 code = TREE_CODE (TREE_OPERAND (arg, 1));
1566 val = iterative_hash_object (code, val);
1567 return iterative_hash_template_arg (TREE_OPERAND (arg, 2), val);
1570 /* layout_type sets structural equality for arrays of
1571 incomplete type, so we can't rely on the canonical type
1573 val = iterative_hash_template_arg (TREE_TYPE (arg), val);
1574 return iterative_hash_template_arg (TYPE_DOMAIN (arg), val);
1577 /* A lambda can't appear in a template arg, but don't crash on
1579 gcc_assert (seen_error ());
1583 case STATIC_CAST_EXPR:
1584 case REINTERPRET_CAST_EXPR:
1585 case CONST_CAST_EXPR:
1586 case DYNAMIC_CAST_EXPR:
1588 val = iterative_hash_template_arg (TREE_TYPE (arg), val);
1589 /* Now hash operands as usual. */
1599 if (TYPE_CANONICAL (arg))
1600 return iterative_hash_object (TYPE_HASH (TYPE_CANONICAL (arg)),
1602 else if (TREE_CODE (arg) == DECLTYPE_TYPE)
1603 return iterative_hash_template_arg (DECLTYPE_TYPE_EXPR (arg), val);
1604 /* Otherwise just compare the types during lookup. */
1607 case tcc_declaration:
1609 return iterative_hash_expr (arg, val);
1612 gcc_assert (IS_EXPR_CODE_CLASS (tclass));
1614 unsigned n = TREE_OPERAND_LENGTH (arg);
1615 for (i = 0; i < n; ++i)
1616 val = iterative_hash_template_arg (TREE_OPERAND (arg, i), val);
1624 /* Unregister the specialization SPEC as a specialization of TMPL.
1625 Replace it with NEW_SPEC, if NEW_SPEC is non-NULL. Returns true
1626 if the SPEC was listed as a specialization of TMPL.
1628 Note that SPEC has been ggc_freed, so we can't look inside it. */
1631 reregister_specialization (tree spec, tree tinfo, tree new_spec)
1636 elt.tmpl = most_general_template (TI_TEMPLATE (tinfo));
1637 elt.args = TI_ARGS (tinfo);
1638 elt.spec = NULL_TREE;
1640 slot = (spec_entry **) htab_find_slot (decl_specializations, &elt, INSERT);
1643 gcc_assert ((*slot)->spec == spec || (*slot)->spec == new_spec);
1644 gcc_assert (new_spec != NULL_TREE);
1645 (*slot)->spec = new_spec;
1652 /* Compare an entry in the local specializations hash table P1 (which
1653 is really a pointer to a TREE_LIST) with P2 (which is really a
1657 eq_local_specializations (const void *p1, const void *p2)
1659 return TREE_VALUE ((const_tree) p1) == (const_tree) p2;
1662 /* Hash P1, an entry in the local specializations table. */
1665 hash_local_specialization (const void* p1)
1667 return htab_hash_pointer (TREE_VALUE ((const_tree) p1));
1670 /* Like register_specialization, but for local declarations. We are
1671 registering SPEC, an instantiation of TMPL. */
1674 register_local_specialization (tree spec, tree tmpl)
1678 slot = htab_find_slot_with_hash (local_specializations, tmpl,
1679 htab_hash_pointer (tmpl), INSERT);
1680 *slot = build_tree_list (spec, tmpl);
1683 /* TYPE is a class type. Returns true if TYPE is an explicitly
1684 specialized class. */
1687 explicit_class_specialization_p (tree type)
1689 if (!CLASSTYPE_TEMPLATE_SPECIALIZATION (type))
1691 return !uses_template_parms (CLASSTYPE_TI_ARGS (type));
1694 /* Print the list of functions at FNS, going through all the overloads
1695 for each element of the list. Alternatively, FNS can not be a
1696 TREE_LIST, in which case it will be printed together with all the
1699 MORE and *STR should respectively be FALSE and NULL when the function
1700 is called from the outside. They are used internally on recursive
1701 calls. print_candidates manages the two parameters and leaves NULL
1702 in *STR when it ends. */
1705 print_candidates_1 (tree fns, bool more, const char **str)
1708 char *spaces = NULL;
1710 for (fn = fns; fn; fn = OVL_NEXT (fn))
1711 if (TREE_CODE (fn) == TREE_LIST)
1713 gcc_assert (!OVL_NEXT (fn) && !is_overloaded_fn (fn));
1714 for (fn2 = fn; fn2 != NULL_TREE; fn2 = TREE_CHAIN (fn2))
1715 print_candidates_1 (TREE_VALUE (fn2),
1716 TREE_CHAIN (fn2) || more, str);
1722 /* Pick the prefix string. */
1723 if (!more && !OVL_NEXT (fns))
1725 error ("candidate is: %+#D", OVL_CURRENT (fn));
1729 *str = _("candidates are:");
1730 spaces = get_spaces (*str);
1732 error ("%s %+#D", *str, OVL_CURRENT (fn));
1733 *str = spaces ? spaces : *str;
1743 /* Print the list of candidate FNS in an error message. */
1746 print_candidates (tree fns)
1748 const char *str = NULL;
1749 print_candidates_1 (fns, false, &str);
1750 gcc_assert (str == NULL);
1753 /* Returns the template (one of the functions given by TEMPLATE_ID)
1754 which can be specialized to match the indicated DECL with the
1755 explicit template args given in TEMPLATE_ID. The DECL may be
1756 NULL_TREE if none is available. In that case, the functions in
1757 TEMPLATE_ID are non-members.
1759 If NEED_MEMBER_TEMPLATE is nonzero the function is known to be a
1760 specialization of a member template.
1762 The TEMPLATE_COUNT is the number of references to qualifying
1763 template classes that appeared in the name of the function. See
1764 check_explicit_specialization for a more accurate description.
1766 TSK indicates what kind of template declaration (if any) is being
1767 declared. TSK_TEMPLATE indicates that the declaration given by
1768 DECL, though a FUNCTION_DECL, has template parameters, and is
1769 therefore a template function.
1771 The template args (those explicitly specified and those deduced)
1772 are output in a newly created vector *TARGS_OUT.
1774 If it is impossible to determine the result, an error message is
1775 issued. The error_mark_node is returned to indicate failure. */
1778 determine_specialization (tree template_id,
1781 int need_member_template,
1787 tree explicit_targs;
1788 tree candidates = NULL_TREE;
1789 /* A TREE_LIST of templates of which DECL may be a specialization.
1790 The TREE_VALUE of each node is a TEMPLATE_DECL. The
1791 corresponding TREE_PURPOSE is the set of template arguments that,
1792 when used to instantiate the template, would produce a function
1793 with the signature of DECL. */
1794 tree templates = NULL_TREE;
1796 struct cp_binding_level *b;
1798 *targs_out = NULL_TREE;
1800 if (template_id == error_mark_node || decl == error_mark_node)
1801 return error_mark_node;
1803 fns = TREE_OPERAND (template_id, 0);
1804 explicit_targs = TREE_OPERAND (template_id, 1);
1806 if (fns == error_mark_node)
1807 return error_mark_node;
1809 /* Check for baselinks. */
1810 if (BASELINK_P (fns))
1811 fns = BASELINK_FUNCTIONS (fns);
1813 if (!is_overloaded_fn (fns))
1815 error ("%qD is not a function template", fns);
1816 return error_mark_node;
1819 /* Count the number of template headers specified for this
1822 for (b = current_binding_level;
1823 b->kind == sk_template_parms;
1827 for (; fns; fns = OVL_NEXT (fns))
1829 tree fn = OVL_CURRENT (fns);
1831 if (TREE_CODE (fn) == TEMPLATE_DECL)
1833 tree decl_arg_types;
1836 /* In case of explicit specialization, we need to check if
1837 the number of template headers appearing in the specialization
1838 is correct. This is usually done in check_explicit_specialization,
1839 but the check done there cannot be exhaustive when specializing
1840 member functions. Consider the following code:
1842 template <> void A<int>::f(int);
1843 template <> template <> void A<int>::f(int);
1845 Assuming that A<int> is not itself an explicit specialization
1846 already, the first line specializes "f" which is a non-template
1847 member function, whilst the second line specializes "f" which
1848 is a template member function. So both lines are syntactically
1849 correct, and check_explicit_specialization does not reject
1852 Here, we can do better, as we are matching the specialization
1853 against the declarations. We count the number of template
1854 headers, and we check if they match TEMPLATE_COUNT + 1
1855 (TEMPLATE_COUNT is the number of qualifying template classes,
1856 plus there must be another header for the member template
1859 Notice that if header_count is zero, this is not a
1860 specialization but rather a template instantiation, so there
1861 is no check we can perform here. */
1862 if (header_count && header_count != template_count + 1)
1865 /* Check that the number of template arguments at the
1866 innermost level for DECL is the same as for FN. */
1867 if (current_binding_level->kind == sk_template_parms
1868 && !current_binding_level->explicit_spec_p
1869 && (TREE_VEC_LENGTH (DECL_INNERMOST_TEMPLATE_PARMS (fn))
1870 != TREE_VEC_LENGTH (INNERMOST_TEMPLATE_PARMS
1871 (current_template_parms))))
1874 /* DECL might be a specialization of FN. */
1875 decl_arg_types = TYPE_ARG_TYPES (TREE_TYPE (decl));
1876 fn_arg_types = TYPE_ARG_TYPES (TREE_TYPE (fn));
1878 /* For a non-static member function, we need to make sure
1879 that the const qualification is the same. Since
1880 get_bindings does not try to merge the "this" parameter,
1881 we must do the comparison explicitly. */
1882 if (DECL_NONSTATIC_MEMBER_FUNCTION_P (fn)
1883 && !same_type_p (TREE_VALUE (fn_arg_types),
1884 TREE_VALUE (decl_arg_types)))
1887 /* Skip the "this" parameter and, for constructors of
1888 classes with virtual bases, the VTT parameter. A
1889 full specialization of a constructor will have a VTT
1890 parameter, but a template never will. */
1892 = skip_artificial_parms_for (decl, decl_arg_types);
1894 = skip_artificial_parms_for (fn, fn_arg_types);
1896 /* Check that the number of function parameters matches.
1898 template <class T> void f(int i = 0);
1899 template <> void f<int>();
1900 The specialization f<int> is invalid but is not caught
1901 by get_bindings below. */
1902 if (list_length (fn_arg_types) != list_length (decl_arg_types))
1905 /* Function templates cannot be specializations; there are
1906 no partial specializations of functions. Therefore, if
1907 the type of DECL does not match FN, there is no
1909 if (tsk == tsk_template)
1911 if (compparms (fn_arg_types, decl_arg_types))
1912 candidates = tree_cons (NULL_TREE, fn, candidates);
1916 /* See whether this function might be a specialization of this
1918 targs = get_bindings (fn, decl, explicit_targs, /*check_ret=*/true);
1921 /* We cannot deduce template arguments that when used to
1922 specialize TMPL will produce DECL. */
1925 /* Save this template, and the arguments deduced. */
1926 templates = tree_cons (targs, fn, templates);
1928 else if (need_member_template)
1929 /* FN is an ordinary member function, and we need a
1930 specialization of a member template. */
1932 else if (TREE_CODE (fn) != FUNCTION_DECL)
1933 /* We can get IDENTIFIER_NODEs here in certain erroneous
1936 else if (!DECL_FUNCTION_MEMBER_P (fn))
1937 /* This is just an ordinary non-member function. Nothing can
1938 be a specialization of that. */
1940 else if (DECL_ARTIFICIAL (fn))
1941 /* Cannot specialize functions that are created implicitly. */
1945 tree decl_arg_types;
1947 /* This is an ordinary member function. However, since
1948 we're here, we can assume it's enclosing class is a
1949 template class. For example,
1951 template <typename T> struct S { void f(); };
1952 template <> void S<int>::f() {}
1954 Here, S<int>::f is a non-template, but S<int> is a
1955 template class. If FN has the same type as DECL, we
1956 might be in business. */
1958 if (!DECL_TEMPLATE_INFO (fn))
1959 /* Its enclosing class is an explicit specialization
1960 of a template class. This is not a candidate. */
1963 if (!same_type_p (TREE_TYPE (TREE_TYPE (decl)),
1964 TREE_TYPE (TREE_TYPE (fn))))
1965 /* The return types differ. */
1968 /* Adjust the type of DECL in case FN is a static member. */
1969 decl_arg_types = TYPE_ARG_TYPES (TREE_TYPE (decl));
1970 if (DECL_STATIC_FUNCTION_P (fn)
1971 && DECL_NONSTATIC_MEMBER_FUNCTION_P (decl))
1972 decl_arg_types = TREE_CHAIN (decl_arg_types);
1974 if (compparms (TYPE_ARG_TYPES (TREE_TYPE (fn)),
1977 candidates = tree_cons (NULL_TREE, fn, candidates);
1981 if (templates && TREE_CHAIN (templates))
1987 It is possible for a specialization with a given function
1988 signature to be instantiated from more than one function
1989 template. In such cases, explicit specification of the
1990 template arguments must be used to uniquely identify the
1991 function template specialization being specialized.
1993 Note that here, there's no suggestion that we're supposed to
1994 determine which of the candidate templates is most
1995 specialized. However, we, also have:
1999 Partial ordering of overloaded function template
2000 declarations is used in the following contexts to select
2001 the function template to which a function template
2002 specialization refers:
2004 -- when an explicit specialization refers to a function
2007 So, we do use the partial ordering rules, at least for now.
2008 This extension can only serve to make invalid programs valid,
2009 so it's safe. And, there is strong anecdotal evidence that
2010 the committee intended the partial ordering rules to apply;
2011 the EDG front end has that behavior, and John Spicer claims
2012 that the committee simply forgot to delete the wording in
2013 [temp.expl.spec]. */
2014 tree tmpl = most_specialized_instantiation (templates);
2015 if (tmpl != error_mark_node)
2018 TREE_CHAIN (templates) = NULL_TREE;
2022 if (templates == NULL_TREE && candidates == NULL_TREE)
2024 error ("template-id %qD for %q+D does not match any template "
2025 "declaration", template_id, decl);
2026 if (header_count && header_count != template_count + 1)
2027 inform (input_location, "saw %d %<template<>%>, need %d for "
2028 "specializing a member function template",
2029 header_count, template_count + 1);
2030 return error_mark_node;
2032 else if ((templates && TREE_CHAIN (templates))
2033 || (candidates && TREE_CHAIN (candidates))
2034 || (templates && candidates))
2036 error ("ambiguous template specialization %qD for %q+D",
2038 candidates = chainon (candidates, templates);
2039 print_candidates (candidates);
2040 return error_mark_node;
2043 /* We have one, and exactly one, match. */
2046 tree fn = TREE_VALUE (candidates);
2047 *targs_out = copy_node (DECL_TI_ARGS (fn));
2048 /* DECL is a re-declaration or partial instantiation of a template
2050 if (TREE_CODE (fn) == TEMPLATE_DECL)
2052 /* It was a specialization of an ordinary member function in a
2054 return DECL_TI_TEMPLATE (fn);
2057 /* It was a specialization of a template. */
2058 targs = DECL_TI_ARGS (DECL_TEMPLATE_RESULT (TREE_VALUE (templates)));
2059 if (TMPL_ARGS_HAVE_MULTIPLE_LEVELS (targs))
2061 *targs_out = copy_node (targs);
2062 SET_TMPL_ARGS_LEVEL (*targs_out,
2063 TMPL_ARGS_DEPTH (*targs_out),
2064 TREE_PURPOSE (templates));
2067 *targs_out = TREE_PURPOSE (templates);
2068 return TREE_VALUE (templates);
2071 /* Returns a chain of parameter types, exactly like the SPEC_TYPES,
2072 but with the default argument values filled in from those in the
2076 copy_default_args_to_explicit_spec_1 (tree spec_types,
2079 tree new_spec_types;
2084 if (spec_types == void_list_node)
2085 return void_list_node;
2087 /* Substitute into the rest of the list. */
2089 copy_default_args_to_explicit_spec_1 (TREE_CHAIN (spec_types),
2090 TREE_CHAIN (tmpl_types));
2092 /* Add the default argument for this parameter. */
2093 return hash_tree_cons (TREE_PURPOSE (tmpl_types),
2094 TREE_VALUE (spec_types),
2098 /* DECL is an explicit specialization. Replicate default arguments
2099 from the template it specializes. (That way, code like:
2101 template <class T> void f(T = 3);
2102 template <> void f(double);
2105 works, as required.) An alternative approach would be to look up
2106 the correct default arguments at the call-site, but this approach
2107 is consistent with how implicit instantiations are handled. */
2110 copy_default_args_to_explicit_spec (tree decl)
2115 tree new_spec_types;
2119 tree object_type = NULL_TREE;
2120 tree in_charge = NULL_TREE;
2121 tree vtt = NULL_TREE;
2123 /* See if there's anything we need to do. */
2124 tmpl = DECL_TI_TEMPLATE (decl);
2125 tmpl_types = TYPE_ARG_TYPES (TREE_TYPE (DECL_TEMPLATE_RESULT (tmpl)));
2126 for (t = tmpl_types; t; t = TREE_CHAIN (t))
2127 if (TREE_PURPOSE (t))
2132 old_type = TREE_TYPE (decl);
2133 spec_types = TYPE_ARG_TYPES (old_type);
2135 if (DECL_NONSTATIC_MEMBER_FUNCTION_P (decl))
2137 /* Remove the this pointer, but remember the object's type for
2139 object_type = TREE_TYPE (TREE_VALUE (spec_types));
2140 spec_types = TREE_CHAIN (spec_types);
2141 tmpl_types = TREE_CHAIN (tmpl_types);
2143 if (DECL_HAS_IN_CHARGE_PARM_P (decl))
2145 /* DECL may contain more parameters than TMPL due to the extra
2146 in-charge parameter in constructors and destructors. */
2147 in_charge = spec_types;
2148 spec_types = TREE_CHAIN (spec_types);
2150 if (DECL_HAS_VTT_PARM_P (decl))
2153 spec_types = TREE_CHAIN (spec_types);
2157 /* Compute the merged default arguments. */
2159 copy_default_args_to_explicit_spec_1 (spec_types, tmpl_types);
2161 /* Compute the new FUNCTION_TYPE. */
2165 new_spec_types = hash_tree_cons (TREE_PURPOSE (vtt),
2170 /* Put the in-charge parameter back. */
2171 new_spec_types = hash_tree_cons (TREE_PURPOSE (in_charge),
2172 TREE_VALUE (in_charge),
2175 new_type = build_method_type_directly (object_type,
2176 TREE_TYPE (old_type),
2180 new_type = build_function_type (TREE_TYPE (old_type),
2182 new_type = cp_build_type_attribute_variant (new_type,
2183 TYPE_ATTRIBUTES (old_type));
2184 new_type = build_exception_variant (new_type,
2185 TYPE_RAISES_EXCEPTIONS (old_type));
2186 TREE_TYPE (decl) = new_type;
2189 /* Check to see if the function just declared, as indicated in
2190 DECLARATOR, and in DECL, is a specialization of a function
2191 template. We may also discover that the declaration is an explicit
2192 instantiation at this point.
2194 Returns DECL, or an equivalent declaration that should be used
2195 instead if all goes well. Issues an error message if something is
2196 amiss. Returns error_mark_node if the error is not easily
2199 FLAGS is a bitmask consisting of the following flags:
2201 2: The function has a definition.
2202 4: The function is a friend.
2204 The TEMPLATE_COUNT is the number of references to qualifying
2205 template classes that appeared in the name of the function. For
2208 template <class T> struct S { void f(); };
2211 the TEMPLATE_COUNT would be 1. However, explicitly specialized
2212 classes are not counted in the TEMPLATE_COUNT, so that in
2214 template <class T> struct S {};
2215 template <> struct S<int> { void f(); }
2216 template <> void S<int>::f();
2218 the TEMPLATE_COUNT would be 0. (Note that this declaration is
2219 invalid; there should be no template <>.)
2221 If the function is a specialization, it is marked as such via
2222 DECL_TEMPLATE_SPECIALIZATION. Furthermore, its DECL_TEMPLATE_INFO
2223 is set up correctly, and it is added to the list of specializations
2224 for that template. */
2227 check_explicit_specialization (tree declarator,
2232 int have_def = flags & 2;
2233 int is_friend = flags & 4;
2234 int specialization = 0;
2235 int explicit_instantiation = 0;
2236 int member_specialization = 0;
2237 tree ctype = DECL_CLASS_CONTEXT (decl);
2238 tree dname = DECL_NAME (decl);
2243 if (!processing_specialization)
2246 tsk = tsk_excessive_parms;
2249 tsk = current_tmpl_spec_kind (template_count);
2254 if (processing_specialization)
2257 SET_DECL_TEMPLATE_SPECIALIZATION (decl);
2259 else if (TREE_CODE (declarator) == TEMPLATE_ID_EXPR)
2262 /* This could be something like:
2264 template <class T> void f(T);
2265 class S { friend void f<>(int); } */
2269 /* This case handles bogus declarations like template <>
2270 template <class T> void f<int>(); */
2272 error ("template-id %qD in declaration of primary template",
2279 case tsk_invalid_member_spec:
2280 /* The error has already been reported in
2281 check_specialization_scope. */
2282 return error_mark_node;
2284 case tsk_invalid_expl_inst:
2285 error ("template parameter list used in explicit instantiation");
2291 error ("definition provided for explicit instantiation");
2293 explicit_instantiation = 1;
2296 case tsk_excessive_parms:
2297 case tsk_insufficient_parms:
2298 if (tsk == tsk_excessive_parms)
2299 error ("too many template parameter lists in declaration of %qD",
2301 else if (template_header_count)
2302 error("too few template parameter lists in declaration of %qD", decl);
2304 error("explicit specialization of %qD must be introduced by "
2305 "%<template <>%>", decl);
2309 SET_DECL_TEMPLATE_SPECIALIZATION (decl);
2311 member_specialization = 1;
2317 if (TREE_CODE (declarator) == TEMPLATE_ID_EXPR)
2319 /* This case handles bogus declarations like template <>
2320 template <class T> void f<int>(); */
2322 if (uses_template_parms (declarator))
2323 error ("function template partial specialization %qD "
2324 "is not allowed", declarator);
2326 error ("template-id %qD in declaration of primary template",
2331 if (ctype && CLASSTYPE_TEMPLATE_INSTANTIATION (ctype))
2332 /* This is a specialization of a member template, without
2333 specialization the containing class. Something like:
2335 template <class T> struct S {
2336 template <class U> void f (U);
2338 template <> template <class U> void S<int>::f(U) {}
2340 That's a specialization -- but of the entire template. */
2348 if (specialization || member_specialization)
2350 tree t = TYPE_ARG_TYPES (TREE_TYPE (decl));
2351 for (; t; t = TREE_CHAIN (t))
2352 if (TREE_PURPOSE (t))
2354 permerror (input_location,
2355 "default argument specified in explicit specialization");
2360 if (specialization || member_specialization || explicit_instantiation)
2362 tree tmpl = NULL_TREE;
2363 tree targs = NULL_TREE;
2365 /* Make sure that the declarator is a TEMPLATE_ID_EXPR. */
2366 if (TREE_CODE (declarator) != TEMPLATE_ID_EXPR)
2370 gcc_assert (TREE_CODE (declarator) == IDENTIFIER_NODE);
2375 /* If there is no class context, the explicit instantiation
2376 must be at namespace scope. */
2377 gcc_assert (DECL_NAMESPACE_SCOPE_P (decl));
2379 /* Find the namespace binding, using the declaration
2381 fns = lookup_qualified_name (CP_DECL_CONTEXT (decl), dname,
2383 if (fns == error_mark_node || !is_overloaded_fn (fns))
2385 error ("%qD is not a template function", dname);
2386 fns = error_mark_node;
2390 tree fn = OVL_CURRENT (fns);
2391 if (!is_associated_namespace (CP_DECL_CONTEXT (decl),
2392 CP_DECL_CONTEXT (fn)))
2393 error ("%qD is not declared in %qD",
2394 decl, current_namespace);
2398 declarator = lookup_template_function (fns, NULL_TREE);
2401 if (declarator == error_mark_node)
2402 return error_mark_node;
2404 if (ctype != NULL_TREE && TYPE_BEING_DEFINED (ctype))
2406 if (!explicit_instantiation)
2407 /* A specialization in class scope. This is invalid,
2408 but the error will already have been flagged by
2409 check_specialization_scope. */
2410 return error_mark_node;
2413 /* It's not valid to write an explicit instantiation in
2416 class C { template void f(); }
2418 This case is caught by the parser. However, on
2421 template class C { void f(); };
2423 (which is invalid) we can get here. The error will be
2430 else if (ctype != NULL_TREE
2431 && (TREE_CODE (TREE_OPERAND (declarator, 0)) ==
2434 /* Find the list of functions in ctype that have the same
2435 name as the declared function. */
2436 tree name = TREE_OPERAND (declarator, 0);
2437 tree fns = NULL_TREE;
2440 if (constructor_name_p (name, ctype))
2442 int is_constructor = DECL_CONSTRUCTOR_P (decl);
2444 if (is_constructor ? !TYPE_HAS_USER_CONSTRUCTOR (ctype)
2445 : !CLASSTYPE_DESTRUCTORS (ctype))
2447 /* From [temp.expl.spec]:
2449 If such an explicit specialization for the member
2450 of a class template names an implicitly-declared
2451 special member function (clause _special_), the
2452 program is ill-formed.
2454 Similar language is found in [temp.explicit]. */
2455 error ("specialization of implicitly-declared special member function");
2456 return error_mark_node;
2459 name = is_constructor ? ctor_identifier : dtor_identifier;
2462 if (!DECL_CONV_FN_P (decl))
2464 idx = lookup_fnfields_1 (ctype, name);
2466 fns = VEC_index (tree, CLASSTYPE_METHOD_VEC (ctype), idx);
2470 VEC(tree,gc) *methods;
2473 /* For a type-conversion operator, we cannot do a
2474 name-based lookup. We might be looking for `operator
2475 int' which will be a specialization of `operator T'.
2476 So, we find *all* the conversion operators, and then
2477 select from them. */
2480 methods = CLASSTYPE_METHOD_VEC (ctype);
2482 for (idx = CLASSTYPE_FIRST_CONVERSION_SLOT;
2483 VEC_iterate (tree, methods, idx, ovl);
2486 if (!DECL_CONV_FN_P (OVL_CURRENT (ovl)))
2487 /* There are no more conversion functions. */
2490 /* Glue all these conversion functions together
2491 with those we already have. */
2492 for (; ovl; ovl = OVL_NEXT (ovl))
2493 fns = ovl_cons (OVL_CURRENT (ovl), fns);
2497 if (fns == NULL_TREE)
2499 error ("no member function %qD declared in %qT", name, ctype);
2500 return error_mark_node;
2503 TREE_OPERAND (declarator, 0) = fns;
2506 /* Figure out what exactly is being specialized at this point.
2507 Note that for an explicit instantiation, even one for a
2508 member function, we cannot tell apriori whether the
2509 instantiation is for a member template, or just a member
2510 function of a template class. Even if a member template is
2511 being instantiated, the member template arguments may be
2512 elided if they can be deduced from the rest of the
2514 tmpl = determine_specialization (declarator, decl,
2516 member_specialization,
2520 if (!tmpl || tmpl == error_mark_node)
2521 /* We couldn't figure out what this declaration was
2523 return error_mark_node;
2526 tree gen_tmpl = most_general_template (tmpl);
2528 if (explicit_instantiation)
2530 /* We don't set DECL_EXPLICIT_INSTANTIATION here; that
2531 is done by do_decl_instantiation later. */
2533 int arg_depth = TMPL_ARGS_DEPTH (targs);
2534 int parm_depth = TMPL_PARMS_DEPTH (DECL_TEMPLATE_PARMS (tmpl));
2536 if (arg_depth > parm_depth)
2538 /* If TMPL is not the most general template (for
2539 example, if TMPL is a friend template that is
2540 injected into namespace scope), then there will
2541 be too many levels of TARGS. Remove some of them
2546 new_targs = make_tree_vec (parm_depth);
2547 for (i = arg_depth - parm_depth; i < arg_depth; ++i)
2548 TREE_VEC_ELT (new_targs, i - (arg_depth - parm_depth))
2549 = TREE_VEC_ELT (targs, i);
2553 return instantiate_template (tmpl, targs, tf_error);
2556 /* If we thought that the DECL was a member function, but it
2557 turns out to be specializing a static member function,
2558 make DECL a static member function as well. */
2559 if (DECL_STATIC_FUNCTION_P (tmpl)
2560 && DECL_NONSTATIC_MEMBER_FUNCTION_P (decl))
2561 revert_static_member_fn (decl);
2563 /* If this is a specialization of a member template of a
2564 template class, we want to return the TEMPLATE_DECL, not
2565 the specialization of it. */
2566 if (tsk == tsk_template)
2568 tree result = DECL_TEMPLATE_RESULT (tmpl);
2569 SET_DECL_TEMPLATE_SPECIALIZATION (tmpl);
2570 DECL_INITIAL (result) = NULL_TREE;
2574 DECL_SOURCE_LOCATION (tmpl) = DECL_SOURCE_LOCATION (decl);
2575 DECL_SOURCE_LOCATION (result)
2576 = DECL_SOURCE_LOCATION (decl);
2577 /* We want to use the argument list specified in the
2578 definition, not in the original declaration. */
2579 DECL_ARGUMENTS (result) = DECL_ARGUMENTS (decl);
2580 for (parm = DECL_ARGUMENTS (result); parm;
2581 parm = DECL_CHAIN (parm))
2582 DECL_CONTEXT (parm) = result;
2584 return register_specialization (tmpl, gen_tmpl, targs,
2588 /* Set up the DECL_TEMPLATE_INFO for DECL. */
2589 DECL_TEMPLATE_INFO (decl) = build_template_info (tmpl, targs);
2591 /* Inherit default function arguments from the template
2592 DECL is specializing. */
2593 copy_default_args_to_explicit_spec (decl);
2595 /* This specialization has the same protection as the
2596 template it specializes. */
2597 TREE_PRIVATE (decl) = TREE_PRIVATE (gen_tmpl);
2598 TREE_PROTECTED (decl) = TREE_PROTECTED (gen_tmpl);
2600 /* 7.1.1-1 [dcl.stc]
2602 A storage-class-specifier shall not be specified in an
2603 explicit specialization...
2605 The parser rejects these, so unless action is taken here,
2606 explicit function specializations will always appear with
2609 The action recommended by the C++ CWG in response to C++
2610 defect report 605 is to make the storage class and linkage
2611 of the explicit specialization match the templated function:
2613 http://www.open-std.org/jtc1/sc22/wg21/docs/cwg_active.html#605
2615 if (tsk == tsk_expl_spec && DECL_FUNCTION_TEMPLATE_P (gen_tmpl))
2617 tree tmpl_func = DECL_TEMPLATE_RESULT (gen_tmpl);
2618 gcc_assert (TREE_CODE (tmpl_func) == FUNCTION_DECL);
2620 /* This specialization has the same linkage and visibility as
2621 the function template it specializes. */
2622 TREE_PUBLIC (decl) = TREE_PUBLIC (tmpl_func);
2623 if (! TREE_PUBLIC (decl))
2625 DECL_INTERFACE_KNOWN (decl) = 1;
2626 DECL_NOT_REALLY_EXTERN (decl) = 1;
2628 DECL_THIS_STATIC (decl) = DECL_THIS_STATIC (tmpl_func);
2629 if (DECL_VISIBILITY_SPECIFIED (tmpl_func))
2631 DECL_VISIBILITY_SPECIFIED (decl) = 1;
2632 DECL_VISIBILITY (decl) = DECL_VISIBILITY (tmpl_func);
2636 /* If DECL is a friend declaration, declared using an
2637 unqualified name, the namespace associated with DECL may
2638 have been set incorrectly. For example, in:
2640 template <typename T> void f(T);
2642 struct S { friend void f<int>(int); }
2645 we will have set the DECL_CONTEXT for the friend
2646 declaration to N, rather than to the global namespace. */
2647 if (DECL_NAMESPACE_SCOPE_P (decl))
2648 DECL_CONTEXT (decl) = DECL_CONTEXT (tmpl);
2650 if (is_friend && !have_def)
2651 /* This is not really a declaration of a specialization.
2652 It's just the name of an instantiation. But, it's not
2653 a request for an instantiation, either. */
2654 SET_DECL_IMPLICIT_INSTANTIATION (decl);
2655 else if (DECL_CONSTRUCTOR_P (decl) || DECL_DESTRUCTOR_P (decl))
2656 /* This is indeed a specialization. In case of constructors
2657 and destructors, we need in-charge and not-in-charge
2658 versions in V3 ABI. */
2659 clone_function_decl (decl, /*update_method_vec_p=*/0);
2661 /* Register this specialization so that we can find it
2663 decl = register_specialization (decl, gen_tmpl, targs, is_friend, 0);
2670 /* Returns 1 iff PARMS1 and PARMS2 are identical sets of template
2671 parameters. These are represented in the same format used for
2672 DECL_TEMPLATE_PARMS. */
2675 comp_template_parms (const_tree parms1, const_tree parms2)
2680 if (parms1 == parms2)
2683 for (p1 = parms1, p2 = parms2;
2684 p1 != NULL_TREE && p2 != NULL_TREE;
2685 p1 = TREE_CHAIN (p1), p2 = TREE_CHAIN (p2))
2687 tree t1 = TREE_VALUE (p1);
2688 tree t2 = TREE_VALUE (p2);
2691 gcc_assert (TREE_CODE (t1) == TREE_VEC);
2692 gcc_assert (TREE_CODE (t2) == TREE_VEC);
2694 if (TREE_VEC_LENGTH (t1) != TREE_VEC_LENGTH (t2))
2697 for (i = 0; i < TREE_VEC_LENGTH (t2); ++i)
2699 tree parm1 = TREE_VALUE (TREE_VEC_ELT (t1, i));
2700 tree parm2 = TREE_VALUE (TREE_VEC_ELT (t2, i));
2702 /* If either of the template parameters are invalid, assume
2703 they match for the sake of error recovery. */
2704 if (parm1 == error_mark_node || parm2 == error_mark_node)
2707 if (TREE_CODE (parm1) != TREE_CODE (parm2))
2710 if (TREE_CODE (parm1) == TEMPLATE_TYPE_PARM
2711 && (TEMPLATE_TYPE_PARAMETER_PACK (parm1)
2712 == TEMPLATE_TYPE_PARAMETER_PACK (parm2)))
2714 else if (!same_type_p (TREE_TYPE (parm1), TREE_TYPE (parm2)))
2719 if ((p1 != NULL_TREE) != (p2 != NULL_TREE))
2720 /* One set of parameters has more parameters lists than the
2727 /* Determine whether PARM is a parameter pack. */
2730 template_parameter_pack_p (const_tree parm)
2732 /* Determine if we have a non-type template parameter pack. */
2733 if (TREE_CODE (parm) == PARM_DECL)
2734 return (DECL_TEMPLATE_PARM_P (parm)
2735 && TEMPLATE_PARM_PARAMETER_PACK (DECL_INITIAL (parm)));
2737 /* If this is a list of template parameters, we could get a
2738 TYPE_DECL or a TEMPLATE_DECL. */
2739 if (TREE_CODE (parm) == TYPE_DECL || TREE_CODE (parm) == TEMPLATE_DECL)
2740 parm = TREE_TYPE (parm);
2742 return ((TREE_CODE (parm) == TEMPLATE_TYPE_PARM
2743 || TREE_CODE (parm) == TEMPLATE_TEMPLATE_PARM)
2744 && TEMPLATE_TYPE_PARAMETER_PACK (parm));
2747 /* Determine if T is a function parameter pack. */
2750 function_parameter_pack_p (const_tree t)
2752 if (t && TREE_CODE (t) == PARM_DECL)
2753 return FUNCTION_PARAMETER_PACK_P (t);
2757 /* Return the function template declaration of PRIMARY_FUNC_TMPL_INST.
2758 PRIMARY_FUNC_TMPL_INST is a primary function template instantiation. */
2761 get_function_template_decl (const_tree primary_func_tmpl_inst)
2763 if (! primary_func_tmpl_inst
2764 || TREE_CODE (primary_func_tmpl_inst) != FUNCTION_DECL
2765 || ! primary_template_instantiation_p (primary_func_tmpl_inst))
2768 return DECL_TEMPLATE_RESULT (DECL_TI_TEMPLATE (primary_func_tmpl_inst));
2771 /* Return true iff the function parameter PARAM_DECL was expanded
2772 from the function parameter pack PACK. */
2775 function_parameter_expanded_from_pack_p (tree param_decl, tree pack)
2777 if (DECL_ARTIFICIAL (param_decl)
2778 || !function_parameter_pack_p (pack))
2781 /* The parameter pack and its pack arguments have the same
2783 return DECL_PARM_INDEX (pack) == DECL_PARM_INDEX (param_decl);
2786 /* Determine whether ARGS describes a variadic template args list,
2787 i.e., one that is terminated by a template argument pack. */
2790 template_args_variadic_p (tree args)
2795 if (args == NULL_TREE)
2798 args = INNERMOST_TEMPLATE_ARGS (args);
2799 nargs = TREE_VEC_LENGTH (args);
2804 last_parm = TREE_VEC_ELT (args, nargs - 1);
2806 return ARGUMENT_PACK_P (last_parm);
2809 /* Generate a new name for the parameter pack name NAME (an
2810 IDENTIFIER_NODE) that incorporates its */
2813 make_ith_pack_parameter_name (tree name, int i)
2815 /* Munge the name to include the parameter index. */
2816 #define NUMBUF_LEN 128
2817 char numbuf[NUMBUF_LEN];
2821 snprintf (numbuf, NUMBUF_LEN, "%i", i);
2822 newname_len = IDENTIFIER_LENGTH (name)
2823 + strlen (numbuf) + 2;
2824 newname = (char*)alloca (newname_len);
2825 snprintf (newname, newname_len,
2826 "%s#%i", IDENTIFIER_POINTER (name), i);
2827 return get_identifier (newname);
2830 /* Return true if T is a primary function
2831 or class template instantiation. */
2834 primary_template_instantiation_p (const_tree t)
2839 if (TREE_CODE (t) == FUNCTION_DECL)
2840 return DECL_LANG_SPECIFIC (t)
2841 && DECL_TEMPLATE_INSTANTIATION (t)
2842 && PRIMARY_TEMPLATE_P (DECL_TI_TEMPLATE (t));
2843 else if (CLASS_TYPE_P (t))
2844 return CLASSTYPE_TEMPLATE_INSTANTIATION (t)
2845 && PRIMARY_TEMPLATE_P (CLASSTYPE_TI_TEMPLATE (t));
2849 /* Return true if PARM is a template template parameter. */
2852 template_template_parameter_p (const_tree parm)
2854 return DECL_TEMPLATE_TEMPLATE_PARM_P (parm);
2857 /* Return the template parameters of T if T is a
2858 primary template instantiation, NULL otherwise. */
2861 get_primary_template_innermost_parameters (const_tree t)
2863 tree parms = NULL, template_info = NULL;
2865 if ((template_info = get_template_info (t))
2866 && primary_template_instantiation_p (t))
2867 parms = INNERMOST_TEMPLATE_PARMS
2868 (DECL_TEMPLATE_PARMS (TI_TEMPLATE (template_info)));
2873 /* Return the template parameters of the LEVELth level from the full list
2874 of template parameters PARMS. */
2877 get_template_parms_at_level (tree parms, int level)
2881 || TREE_CODE (parms) != TREE_LIST
2882 || level > TMPL_PARMS_DEPTH (parms))
2885 for (p = parms; p; p = TREE_CHAIN (p))
2886 if (TMPL_PARMS_DEPTH (p) == level)
2892 /* Returns the template arguments of T if T is a template instantiation,
2896 get_template_innermost_arguments (const_tree t)
2898 tree args = NULL, template_info = NULL;
2900 if ((template_info = get_template_info (t))
2901 && TI_ARGS (template_info))
2902 args = INNERMOST_TEMPLATE_ARGS (TI_ARGS (template_info));
2907 /* Return the argument pack elements of T if T is a template argument pack,
2911 get_template_argument_pack_elems (const_tree t)
2913 if (TREE_CODE (t) != TYPE_ARGUMENT_PACK
2914 && TREE_CODE (t) != NONTYPE_ARGUMENT_PACK)
2917 return ARGUMENT_PACK_ARGS (t);
2920 /* Structure used to track the progress of find_parameter_packs_r. */
2921 struct find_parameter_pack_data
2923 /* TREE_LIST that will contain all of the parameter packs found by
2925 tree* parameter_packs;
2927 /* Set of AST nodes that have been visited by the traversal. */
2928 struct pointer_set_t *visited;
2931 /* Identifies all of the argument packs that occur in a template
2932 argument and appends them to the TREE_LIST inside DATA, which is a
2933 find_parameter_pack_data structure. This is a subroutine of
2934 make_pack_expansion and uses_parameter_packs. */
2936 find_parameter_packs_r (tree *tp, int *walk_subtrees, void* data)
2939 struct find_parameter_pack_data* ppd =
2940 (struct find_parameter_pack_data*)data;
2941 bool parameter_pack_p = false;
2943 /* Identify whether this is a parameter pack or not. */
2944 switch (TREE_CODE (t))
2946 case TEMPLATE_PARM_INDEX:
2947 if (TEMPLATE_PARM_PARAMETER_PACK (t))
2948 parameter_pack_p = true;
2951 case TEMPLATE_TYPE_PARM:
2952 case TEMPLATE_TEMPLATE_PARM:
2953 if (TEMPLATE_TYPE_PARAMETER_PACK (t))
2954 parameter_pack_p = true;
2958 if (FUNCTION_PARAMETER_PACK_P (t))
2960 /* We don't want to walk into the type of a PARM_DECL,
2961 because we don't want to see the type parameter pack. */
2963 parameter_pack_p = true;
2968 /* Not a parameter pack. */
2972 if (parameter_pack_p)
2974 /* Add this parameter pack to the list. */
2975 *ppd->parameter_packs = tree_cons (NULL_TREE, t, *ppd->parameter_packs);
2979 cp_walk_tree (&TYPE_CONTEXT (t),
2980 &find_parameter_packs_r, ppd, ppd->visited);
2982 /* This switch statement will return immediately if we don't find a
2984 switch (TREE_CODE (t))
2986 case TEMPLATE_PARM_INDEX:
2989 case BOUND_TEMPLATE_TEMPLATE_PARM:
2990 /* Check the template itself. */
2991 cp_walk_tree (&TREE_TYPE (TYPE_TI_TEMPLATE (t)),
2992 &find_parameter_packs_r, ppd, ppd->visited);
2993 /* Check the template arguments. */
2994 cp_walk_tree (&TYPE_TI_ARGS (t), &find_parameter_packs_r, ppd,
2999 case TEMPLATE_TYPE_PARM:
3000 case TEMPLATE_TEMPLATE_PARM:
3007 if (TYPE_PTRMEMFUNC_P (t))
3013 if (TYPE_TEMPLATE_INFO (t))
3014 cp_walk_tree (&TI_ARGS (TYPE_TEMPLATE_INFO (t)),
3015 &find_parameter_packs_r, ppd, ppd->visited);
3021 cp_walk_tree (&TREE_TYPE (t),
3022 &find_parameter_packs_r, ppd, ppd->visited);
3026 cp_walk_tree (&TYPENAME_TYPE_FULLNAME (t), &find_parameter_packs_r,
3031 case TYPE_PACK_EXPANSION:
3032 case EXPR_PACK_EXPANSION:
3037 cp_walk_tree (&TYPE_MAX_VALUE (t), &find_parameter_packs_r,
3042 case IDENTIFIER_NODE:
3043 cp_walk_tree (&TREE_TYPE (t), &find_parameter_packs_r, ppd,
3055 /* Determines if the expression or type T uses any parameter packs. */
3057 uses_parameter_packs (tree t)
3059 tree parameter_packs = NULL_TREE;
3060 struct find_parameter_pack_data ppd;
3061 ppd.parameter_packs = ¶meter_packs;
3062 ppd.visited = pointer_set_create ();
3063 cp_walk_tree (&t, &find_parameter_packs_r, &ppd, ppd.visited);
3064 pointer_set_destroy (ppd.visited);
3065 return parameter_packs != NULL_TREE;
3068 /* Turn ARG, which may be an expression, type, or a TREE_LIST
3069 representation a base-class initializer into a parameter pack
3070 expansion. If all goes well, the resulting node will be an
3071 EXPR_PACK_EXPANSION, TYPE_PACK_EXPANSION, or TREE_LIST,
3074 make_pack_expansion (tree arg)
3077 tree parameter_packs = NULL_TREE;
3078 bool for_types = false;
3079 struct find_parameter_pack_data ppd;
3081 if (!arg || arg == error_mark_node)
3084 if (TREE_CODE (arg) == TREE_LIST)
3086 /* The only time we will see a TREE_LIST here is for a base
3087 class initializer. In this case, the TREE_PURPOSE will be a
3088 _TYPE node (representing the base class expansion we're
3089 initializing) and the TREE_VALUE will be a TREE_LIST
3090 containing the initialization arguments.
3092 The resulting expansion looks somewhat different from most
3093 expansions. Rather than returning just one _EXPANSION, we
3094 return a TREE_LIST whose TREE_PURPOSE is a
3095 TYPE_PACK_EXPANSION containing the bases that will be
3096 initialized. The TREE_VALUE will be identical to the
3097 original TREE_VALUE, which is a list of arguments that will
3098 be passed to each base. We do not introduce any new pack
3099 expansion nodes into the TREE_VALUE (although it is possible
3100 that some already exist), because the TREE_PURPOSE and
3101 TREE_VALUE all need to be expanded together with the same
3102 _EXPANSION node. Note that the TYPE_PACK_EXPANSION in the
3103 resulting TREE_PURPOSE will mention the parameter packs in
3104 both the bases and the arguments to the bases. */
3107 tree parameter_packs = NULL_TREE;
3109 /* Determine which parameter packs will be used by the base
3111 ppd.visited = pointer_set_create ();
3112 ppd.parameter_packs = ¶meter_packs;
3113 cp_walk_tree (&TREE_PURPOSE (arg), &find_parameter_packs_r,
3116 if (parameter_packs == NULL_TREE)
3118 error ("base initializer expansion %<%T%> contains no parameter packs", arg);
3119 pointer_set_destroy (ppd.visited);
3120 return error_mark_node;
3123 if (TREE_VALUE (arg) != void_type_node)
3125 /* Collect the sets of parameter packs used in each of the
3126 initialization arguments. */
3127 for (value = TREE_VALUE (arg); value; value = TREE_CHAIN (value))
3129 /* Determine which parameter packs will be expanded in this
3131 cp_walk_tree (&TREE_VALUE (value), &find_parameter_packs_r,
3136 pointer_set_destroy (ppd.visited);
3138 /* Create the pack expansion type for the base type. */
3139 purpose = cxx_make_type (TYPE_PACK_EXPANSION);
3140 SET_PACK_EXPANSION_PATTERN (purpose, TREE_PURPOSE (arg));
3141 PACK_EXPANSION_PARAMETER_PACKS (purpose) = parameter_packs;
3143 /* Just use structural equality for these TYPE_PACK_EXPANSIONS;
3144 they will rarely be compared to anything. */
3145 SET_TYPE_STRUCTURAL_EQUALITY (purpose);
3147 return tree_cons (purpose, TREE_VALUE (arg), NULL_TREE);
3150 if (TYPE_P (arg) || TREE_CODE (arg) == TEMPLATE_DECL)
3153 /* Build the PACK_EXPANSION_* node. */
3155 ? cxx_make_type (TYPE_PACK_EXPANSION)
3156 : make_node (EXPR_PACK_EXPANSION);
3157 SET_PACK_EXPANSION_PATTERN (result, arg);
3158 if (TREE_CODE (result) == EXPR_PACK_EXPANSION)
3160 /* Propagate type and const-expression information. */
3161 TREE_TYPE (result) = TREE_TYPE (arg);
3162 TREE_CONSTANT (result) = TREE_CONSTANT (arg);
3165 /* Just use structural equality for these TYPE_PACK_EXPANSIONS;
3166 they will rarely be compared to anything. */
3167 SET_TYPE_STRUCTURAL_EQUALITY (result);
3169 /* Determine which parameter packs will be expanded. */
3170 ppd.parameter_packs = ¶meter_packs;
3171 ppd.visited = pointer_set_create ();
3172 cp_walk_tree (&arg, &find_parameter_packs_r, &ppd, ppd.visited);
3173 pointer_set_destroy (ppd.visited);
3175 /* Make sure we found some parameter packs. */
3176 if (parameter_packs == NULL_TREE)
3179 error ("expansion pattern %<%T%> contains no argument packs", arg);
3181 error ("expansion pattern %<%E%> contains no argument packs", arg);
3182 return error_mark_node;
3184 PACK_EXPANSION_PARAMETER_PACKS (result) = parameter_packs;
3189 /* Checks T for any "bare" parameter packs, which have not yet been
3190 expanded, and issues an error if any are found. This operation can
3191 only be done on full expressions or types (e.g., an expression
3192 statement, "if" condition, etc.), because we could have expressions like:
3194 foo(f(g(h(args)))...)
3196 where "args" is a parameter pack. check_for_bare_parameter_packs
3197 should not be called for the subexpressions args, h(args),
3198 g(h(args)), or f(g(h(args))), because we would produce erroneous
3201 Returns TRUE and emits an error if there were bare parameter packs,
3202 returns FALSE otherwise. */
3204 check_for_bare_parameter_packs (tree t)
3206 tree parameter_packs = NULL_TREE;
3207 struct find_parameter_pack_data ppd;
3209 if (!processing_template_decl || !t || t == error_mark_node)
3212 if (TREE_CODE (t) == TYPE_DECL)
3215 ppd.parameter_packs = ¶meter_packs;
3216 ppd.visited = pointer_set_create ();
3217 cp_walk_tree (&t, &find_parameter_packs_r, &ppd, ppd.visited);
3218 pointer_set_destroy (ppd.visited);
3220 if (parameter_packs)
3222 error ("parameter packs not expanded with %<...%>:");
3223 while (parameter_packs)
3225 tree pack = TREE_VALUE (parameter_packs);
3226 tree name = NULL_TREE;
3228 if (TREE_CODE (pack) == TEMPLATE_TYPE_PARM
3229 || TREE_CODE (pack) == TEMPLATE_TEMPLATE_PARM)
3230 name = TYPE_NAME (pack);
3231 else if (TREE_CODE (pack) == TEMPLATE_PARM_INDEX)
3232 name = DECL_NAME (TEMPLATE_PARM_DECL (pack));
3234 name = DECL_NAME (pack);
3237 inform (input_location, " %qD", name);
3239 inform (input_location, " <anonymous>");
3241 parameter_packs = TREE_CHAIN (parameter_packs);
3250 /* Expand any parameter packs that occur in the template arguments in
3253 expand_template_argument_pack (tree args)
3255 tree result_args = NULL_TREE;
3256 int in_arg, out_arg = 0, nargs = args ? TREE_VEC_LENGTH (args) : 0;
3257 int num_result_args = -1;
3258 int non_default_args_count = -1;
3260 /* First, determine if we need to expand anything, and the number of
3261 slots we'll need. */
3262 for (in_arg = 0; in_arg < nargs; ++in_arg)
3264 tree arg = TREE_VEC_ELT (args, in_arg);
3265 if (arg == NULL_TREE)
3267 if (ARGUMENT_PACK_P (arg))
3269 int num_packed = TREE_VEC_LENGTH (ARGUMENT_PACK_ARGS (arg));
3270 if (num_result_args < 0)
3271 num_result_args = in_arg + num_packed;
3273 num_result_args += num_packed;
3277 if (num_result_args >= 0)
3282 /* If no expansion is necessary, we're done. */
3283 if (num_result_args < 0)
3286 /* Expand arguments. */
3287 result_args = make_tree_vec (num_result_args);
3288 if (NON_DEFAULT_TEMPLATE_ARGS_COUNT (args))
3289 non_default_args_count =
3290 GET_NON_DEFAULT_TEMPLATE_ARGS_COUNT (args);
3291 for (in_arg = 0; in_arg < nargs; ++in_arg)
3293 tree arg = TREE_VEC_ELT (args, in_arg);
3294 if (ARGUMENT_PACK_P (arg))
3296 tree packed = ARGUMENT_PACK_ARGS (arg);
3297 int i, num_packed = TREE_VEC_LENGTH (packed);
3298 for (i = 0; i < num_packed; ++i, ++out_arg)
3299 TREE_VEC_ELT (result_args, out_arg) = TREE_VEC_ELT(packed, i);
3300 if (non_default_args_count > 0)
3301 non_default_args_count += num_packed;
3305 TREE_VEC_ELT (result_args, out_arg) = arg;
3309 if (non_default_args_count >= 0)
3310 SET_NON_DEFAULT_TEMPLATE_ARGS_COUNT (result_args, non_default_args_count);
3314 /* Checks if DECL shadows a template parameter.
3316 [temp.local]: A template-parameter shall not be redeclared within its
3317 scope (including nested scopes).
3319 Emits an error and returns TRUE if the DECL shadows a parameter,
3320 returns FALSE otherwise. */
3323 check_template_shadow (tree decl)
3327 /* If we're not in a template, we can't possibly shadow a template
3329 if (!current_template_parms)
3332 /* Figure out what we're shadowing. */
3333 if (TREE_CODE (decl) == OVERLOAD)
3334 decl = OVL_CURRENT (decl);
3335 olddecl = innermost_non_namespace_value (DECL_NAME (decl));
3337 /* If there's no previous binding for this name, we're not shadowing
3338 anything, let alone a template parameter. */
3342 /* If we're not shadowing a template parameter, we're done. Note
3343 that OLDDECL might be an OVERLOAD (or perhaps even an
3344 ERROR_MARK), so we can't just blithely assume it to be a _DECL
3346 if (!DECL_P (olddecl) || !DECL_TEMPLATE_PARM_P (olddecl))
3349 /* We check for decl != olddecl to avoid bogus errors for using a
3350 name inside a class. We check TPFI to avoid duplicate errors for
3351 inline member templates. */
3353 || TEMPLATE_PARMS_FOR_INLINE (current_template_parms))
3356 error ("declaration of %q+#D", decl);
3357 error (" shadows template parm %q+#D", olddecl);
3361 /* Return a new TEMPLATE_PARM_INDEX with the indicated INDEX, LEVEL,
3362 ORIG_LEVEL, DECL, and TYPE. NUM_SIBLINGS is the total number of
3363 template parameters. */
3366 build_template_parm_index (int index,
3373 tree t = make_node (TEMPLATE_PARM_INDEX);
3374 TEMPLATE_PARM_IDX (t) = index;
3375 TEMPLATE_PARM_LEVEL (t) = level;
3376 TEMPLATE_PARM_ORIG_LEVEL (t) = orig_level;
3377 TEMPLATE_PARM_NUM_SIBLINGS (t) = num_siblings;
3378 TEMPLATE_PARM_DECL (t) = decl;
3379 TREE_TYPE (t) = type;
3380 TREE_CONSTANT (t) = TREE_CONSTANT (decl);
3381 TREE_READONLY (t) = TREE_READONLY (decl);
3386 /* Find the canonical type parameter for the given template type
3387 parameter. Returns the canonical type parameter, which may be TYPE
3388 if no such parameter existed. */
3391 canonical_type_parameter (tree type)
3394 int idx = TEMPLATE_TYPE_IDX (type);
3395 if (!canonical_template_parms)
3396 canonical_template_parms = VEC_alloc (tree, gc, idx+1);
3398 while (VEC_length (tree, canonical_template_parms) <= (unsigned)idx)
3399 VEC_safe_push (tree, gc, canonical_template_parms, NULL_TREE);
3401 list = VEC_index (tree, canonical_template_parms, idx);
3402 while (list && !comptypes (type, TREE_VALUE (list), COMPARE_STRUCTURAL))
3403 list = TREE_CHAIN (list);
3406 return TREE_VALUE (list);
3409 VEC_replace(tree, canonical_template_parms, idx,
3410 tree_cons (NULL_TREE, type,
3411 VEC_index (tree, canonical_template_parms, idx)));
3416 /* Return a TEMPLATE_PARM_INDEX, similar to INDEX, but whose
3417 TEMPLATE_PARM_LEVEL has been decreased by LEVELS. If such a
3418 TEMPLATE_PARM_INDEX already exists, it is returned; otherwise, a
3419 new one is created. */
3422 reduce_template_parm_level (tree index, tree type, int levels, tree args,
3423 tsubst_flags_t complain)
3425 if (TEMPLATE_PARM_DESCENDANTS (index) == NULL_TREE
3426 || (TEMPLATE_PARM_LEVEL (TEMPLATE_PARM_DESCENDANTS (index))
3427 != TEMPLATE_PARM_LEVEL (index) - levels)
3428 || !same_type_p (type, TREE_TYPE (TEMPLATE_PARM_DESCENDANTS (index))))
3430 tree orig_decl = TEMPLATE_PARM_DECL (index);
3433 decl = build_decl (DECL_SOURCE_LOCATION (orig_decl),
3434 TREE_CODE (orig_decl), DECL_NAME (orig_decl), type);
3435 TREE_CONSTANT (decl) = TREE_CONSTANT (orig_decl);
3436 TREE_READONLY (decl) = TREE_READONLY (orig_decl);
3437 DECL_ARTIFICIAL (decl) = 1;
3438 SET_DECL_TEMPLATE_PARM_P (decl);
3440 t = build_template_parm_index (TEMPLATE_PARM_IDX (index),
3441 TEMPLATE_PARM_LEVEL (index) - levels,
3442 TEMPLATE_PARM_ORIG_LEVEL (index),
3443 TEMPLATE_PARM_NUM_SIBLINGS (index),
3445 TEMPLATE_PARM_DESCENDANTS (index) = t;
3446 TEMPLATE_PARM_PARAMETER_PACK (t)
3447 = TEMPLATE_PARM_PARAMETER_PACK (index);
3449 /* Template template parameters need this. */
3450 if (TREE_CODE (decl) == TEMPLATE_DECL)
3451 DECL_TEMPLATE_PARMS (decl) = tsubst_template_parms
3452 (DECL_TEMPLATE_PARMS (TEMPLATE_PARM_DECL (index)),
3456 return TEMPLATE_PARM_DESCENDANTS (index);
3459 /* Process information from new template parameter PARM and append it
3460 to the LIST being built. This new parameter is a non-type
3461 parameter iff IS_NON_TYPE is true. This new parameter is a
3462 parameter pack iff IS_PARAMETER_PACK is true. The location of PARM
3463 is in PARM_LOC. NUM_TEMPLATE_PARMS is the size of the template
3464 parameter list PARM belongs to. This is used used to create a
3465 proper canonical type for the type of PARM that is to be created,
3466 iff PARM is a type. If the size is not known, this parameter shall
3470 process_template_parm (tree list, location_t parm_loc, tree parm,
3471 bool is_non_type, bool is_parameter_pack,
3472 unsigned num_template_parms)
3479 gcc_assert (TREE_CODE (parm) == TREE_LIST);
3480 defval = TREE_PURPOSE (parm);
3484 tree p = tree_last (list);
3486 if (p && TREE_VALUE (p) != error_mark_node)
3489 if (TREE_CODE (p) == TYPE_DECL || TREE_CODE (p) == TEMPLATE_DECL)
3490 idx = TEMPLATE_TYPE_IDX (TREE_TYPE (p));
3492 idx = TEMPLATE_PARM_IDX (DECL_INITIAL (p));
3502 parm = TREE_VALUE (parm);
3504 SET_DECL_TEMPLATE_PARM_P (parm);
3506 if (TREE_TYPE (parm) == error_mark_node)
3508 err_parm_list = build_tree_list (defval, parm);
3509 TREE_VALUE (err_parm_list) = error_mark_node;
3510 return chainon (list, err_parm_list);
3516 The top-level cv-qualifiers on the template-parameter are
3517 ignored when determining its type. */
3518 TREE_TYPE (parm) = TYPE_MAIN_VARIANT (TREE_TYPE (parm));
3519 if (invalid_nontype_parm_type_p (TREE_TYPE (parm), 1))
3521 err_parm_list = build_tree_list (defval, parm);
3522 TREE_VALUE (err_parm_list) = error_mark_node;
3523 return chainon (list, err_parm_list);
3526 if (uses_parameter_packs (TREE_TYPE (parm)) && !is_parameter_pack)
3528 /* This template parameter is not a parameter pack, but it
3529 should be. Complain about "bare" parameter packs. */
3530 check_for_bare_parameter_packs (TREE_TYPE (parm));
3532 /* Recover by calling this a parameter pack. */
3533 is_parameter_pack = true;
3537 /* A template parameter is not modifiable. */
3538 TREE_CONSTANT (parm) = 1;
3539 TREE_READONLY (parm) = 1;
3540 decl = build_decl (parm_loc,
3541 CONST_DECL, DECL_NAME (parm), TREE_TYPE (parm));
3542 TREE_CONSTANT (decl) = 1;
3543 TREE_READONLY (decl) = 1;
3544 DECL_INITIAL (parm) = DECL_INITIAL (decl)
3545 = build_template_parm_index (idx, processing_template_decl,
3546 processing_template_decl,
3548 decl, TREE_TYPE (parm));
3550 TEMPLATE_PARM_PARAMETER_PACK (DECL_INITIAL (parm))
3551 = is_parameter_pack;
3556 parm = TREE_VALUE (TREE_VALUE (parm));
3558 if (parm && TREE_CODE (parm) == TEMPLATE_DECL)
3560 t = cxx_make_type (TEMPLATE_TEMPLATE_PARM);
3561 /* This is for distinguishing between real templates and template
3562 template parameters */
3563 TREE_TYPE (parm) = t;
3564 TREE_TYPE (DECL_TEMPLATE_RESULT (parm)) = t;
3569 t = cxx_make_type (TEMPLATE_TYPE_PARM);
3570 /* parm is either IDENTIFIER_NODE or NULL_TREE. */
3571 decl = build_decl (parm_loc,
3572 TYPE_DECL, parm, t);
3575 TYPE_NAME (t) = decl;
3576 TYPE_STUB_DECL (t) = decl;
3578 TEMPLATE_TYPE_PARM_INDEX (t)
3579 = build_template_parm_index (idx, processing_template_decl,
3580 processing_template_decl,
3582 decl, TREE_TYPE (parm));
3583 TEMPLATE_TYPE_PARAMETER_PACK (t) = is_parameter_pack;
3584 TYPE_CANONICAL (t) = canonical_type_parameter (t);
3586 DECL_ARTIFICIAL (decl) = 1;
3587 SET_DECL_TEMPLATE_PARM_P (decl);
3589 parm = build_tree_list (defval, parm);
3590 return chainon (list, parm);
3593 /* The end of a template parameter list has been reached. Process the
3594 tree list into a parameter vector, converting each parameter into a more
3595 useful form. Type parameters are saved as IDENTIFIER_NODEs, and others
3599 end_template_parm_list (tree parms)
3603 tree saved_parmlist = make_tree_vec (list_length (parms));
3605 current_template_parms
3606 = tree_cons (size_int (processing_template_decl),
3607 saved_parmlist, current_template_parms);
3609 for (parm = parms, nparms = 0; parm; parm = next, nparms++)
3611 next = TREE_CHAIN (parm);
3612 TREE_VEC_ELT (saved_parmlist, nparms) = parm;
3613 TREE_CHAIN (parm) = NULL_TREE;
3616 --processing_template_parmlist;
3618 return saved_parmlist;
3621 /* Create a new type almost identical to TYPE but which has the
3622 following differences:
3624 1/ T has a new TEMPLATE_PARM_INDEX that carries the new number of
3625 template sibling parameters of T.
3627 2/ T has a new canonical type that matches the new number
3630 3/ From now on, T is going to be what lookups referring to the
3631 name of TYPE will return. No lookup should return TYPE anymore.
3633 NUM_PARMS is the new number of sibling parms TYPE belongs to.
3635 This is a subroutine of fixup_template_parms. */
3638 fixup_template_type_parm_type (tree type, int num_parms)
3640 tree orig_idx = TEMPLATE_TYPE_PARM_INDEX (type), idx;
3642 /* This is the decl which name is inserted into the symbol table for
3643 the template parm type. So whenever we lookup the type name, this
3644 is the DECL we get. */
3647 /* Do not fix up the type twice. */
3648 if (orig_idx && TEMPLATE_PARM_NUM_SIBLINGS (orig_idx) != 0)
3651 t = copy_type (type);
3652 decl = TYPE_NAME (t);
3654 TYPE_MAIN_VARIANT (t) = t;
3655 TYPE_NEXT_VARIANT (t)= NULL_TREE;
3656 TYPE_POINTER_TO (t) = 0;
3657 TYPE_REFERENCE_TO (t) = 0;
3659 idx = build_template_parm_index (TEMPLATE_PARM_IDX (orig_idx),
3660 TEMPLATE_PARM_LEVEL (orig_idx),
3661 TEMPLATE_PARM_ORIG_LEVEL (orig_idx),
3664 TEMPLATE_PARM_DESCENDANTS (idx) = TEMPLATE_PARM_DESCENDANTS (orig_idx);
3665 TEMPLATE_PARM_PARAMETER_PACK (idx) = TEMPLATE_PARM_PARAMETER_PACK (orig_idx);
3666 TEMPLATE_TYPE_PARM_INDEX (t) = idx;
3668 TYPE_STUB_DECL (t) = decl;
3669 TEMPLATE_TYPE_DECL (t) = decl;
3670 if (TREE_CODE (type) == TEMPLATE_TEMPLATE_PARM)
3671 TREE_TYPE (DECL_TEMPLATE_RESULT (decl)) = t;
3673 /* Update the type associated to the type name stored in the symbol
3674 table. Now, whenever the type name is looked up, the resulting
3675 type is properly fixed up. */
3676 TREE_TYPE (decl) = t;
3678 TYPE_CANONICAL (t) = canonical_type_parameter (t);
3683 /* Create and return a new TEMPLATE_PARM_INDEX that is almost
3684 identical to I, but that is fixed up as to:
3686 1/ carry the number of sibling parms (NUM_PARMS) of the template
3687 parm represented by I.
3689 2/ replace all references to template parm types declared before I
3690 (in the same template parm list as I) by references to template
3691 parm types contained in ARGS. ARGS should contain the list of
3692 template parms that have been fixed up so far, in a form suitable
3693 to be passed to tsubst.
3695 This is a subroutine of fixup_template_parms. */
3698 fixup_template_parm_index (tree i, tree args, int num_parms)
3700 tree index, decl, type;
3703 || TREE_CODE (i) != TEMPLATE_PARM_INDEX
3704 /* Do not fix up the index twice. */
3705 || (TEMPLATE_PARM_NUM_SIBLINGS (i) != 0))
3708 decl = TEMPLATE_PARM_DECL (i);
3709 type = TREE_TYPE (decl);
3711 index = build_template_parm_index (TEMPLATE_PARM_IDX (i),
3712 TEMPLATE_PARM_LEVEL (i),
3713 TEMPLATE_PARM_ORIG_LEVEL (i),
3717 TEMPLATE_PARM_DESCENDANTS (index) = TEMPLATE_PARM_DESCENDANTS (i);
3718 TEMPLATE_PARM_PARAMETER_PACK (index) = TEMPLATE_PARM_PARAMETER_PACK (i);
3720 type = tsubst (type, args, tf_none, NULL_TREE);
3722 TREE_TYPE (decl) = type;
3723 TREE_TYPE (index) = type;
3729 This is a subroutine of fixup_template_parms.
3731 It computes the canonical type of the type of the template
3732 parameter PARM_DESC and update all references to that type so that
3733 they use the newly computed canonical type. No access check is
3734 performed during the fixup. PARM_DESC is a TREE_LIST which
3735 TREE_VALUE is the template parameter and its TREE_PURPOSE is the
3736 default argument of the template parm if any. IDX is the index of
3737 the template parameter, starting at 0. NUM_PARMS is the number of
3738 template parameters in the set PARM_DESC belongs to. ARGLIST is a
3739 TREE_VEC containing the full set of template parameters in a form
3740 suitable to be passed to substs functions as their ARGS
3741 argument. This is what current_template_args returns for a given
3742 template. The innermost vector of args in ARGLIST is the set of
3743 template parms that have been fixed up so far. This function adds
3744 the fixed up parameter into that vector. */
3747 fixup_template_parm (tree parm_desc,
3752 tree parm = TREE_VALUE (parm_desc);
3753 tree fixedup_args = INNERMOST_TEMPLATE_ARGS (arglist);
3755 push_deferring_access_checks (dk_no_check);
3757 if (TREE_CODE (parm) == TYPE_DECL)
3759 /* PARM is a template type parameter. Fix up its type, add
3760 the fixed-up template parm to the vector of fixed-up
3761 template parms so far, and substitute the fixed-up
3762 template parms into the default argument of this
3765 fixup_template_type_parm_type (TREE_TYPE (parm), num_parms);
3766 TREE_TYPE (parm) = t;
3768 TREE_VEC_ELT (fixedup_args, idx) = template_parm_to_arg (parm_desc);
3770 else if (TREE_CODE (parm) == TEMPLATE_DECL)
3772 /* PARM is a template template parameter. This is going to
3774 tree tparms, targs, innermost_args, t;
3777 /* First, fix up the parms of the template template parm
3778 because the parms are involved in defining the new canonical
3779 type of the template template parm. */
3781 /* So we need to substitute the template parm types that have
3782 been fixed up so far into the template parms of this template
3783 template parm. E.g, consider this:
3785 template<class T, template<T u> class TT> class S;
3787 In this case we want to substitute T into the
3788 template parameters of TT.
3790 So let's walk the template parms of PARM here, and
3791 tsubst ARGLIST into into each of the template
3794 /* For this substitution we need to build the full set of
3795 template parameters and use that as arguments for the
3796 tsubsting function. */
3797 tparms = INNERMOST_TEMPLATE_PARMS (DECL_TEMPLATE_PARMS (parm));
3799 /* This will contain the innermost parms of PARM into which
3800 we have substituted so far. */
3801 innermost_args = make_tree_vec (TREE_VEC_LENGTH (tparms));
3802 targs = add_to_template_args (arglist, innermost_args);
3803 for (j = 0; j < TREE_VEC_LENGTH (tparms); ++j)
3807 parameter = TREE_VEC_ELT (tparms, j);
3809 /* INNERMOST_ARGS needs to have at least the same number
3810 of elements as the index PARAMETER, ortherwise
3811 tsubsting into PARAMETER will result in partially
3812 instantiating it, reducing its tempate parm
3813 level. Let's tactically fill INNERMOST_ARGS for that
3815 TREE_VEC_ELT (innermost_args, j) =
3816 template_parm_to_arg (parameter);
3818 fixup_template_parm (parameter, j,
3819 TREE_VEC_LENGTH (tparms),
3823 /* Now fix up the type of the template template parm. */
3825 t = fixup_template_type_parm_type (TREE_TYPE (parm), num_parms);
3826 TREE_TYPE (parm) = t;
3828 TREE_VEC_ELT (fixedup_args, idx) =
3829 template_parm_to_arg (parm_desc);
3831 else if (TREE_CODE (parm) == PARM_DECL)
3833 /* PARM is a non-type template parameter. We need to:
3835 * Fix up its TEMPLATE_PARM_INDEX to make it carry the
3836 proper number of sibling parameters.
3838 * Make lookups of the template parameter return a reference
3839 to the fixed-up index. No lookup should return references
3840 to the former index anymore.
3842 * Substitute the template parms that got fixed up so far
3844 * into the type of PARM. */
3846 tree index = DECL_INITIAL (parm);
3848 /* PUSHED_DECL is the decl added to the symbol table with
3849 the name of the parameter. E,g:
3851 template<class T, T u> //#0
3852 auto my_function(T t) -> decltype(u); //#1
3854 Here, when looking up u at //#1, we get the decl of u
3855 resulting from the declaration in #0. This is what
3856 PUSHED_DECL is. We need to replace the reference to the
3857 old TEMPLATE_PARM_INDEX carried by PUSHED_DECL by the
3858 fixed-up TEMPLATE_PARM_INDEX. */
3859 tree pushed_decl = TEMPLATE_PARM_DECL (index);
3861 /* Let's fix up the TEMPLATE_PARM_INDEX then. Note that we must
3862 fixup the type of PUSHED_DECL as well and luckily
3863 fixup_template_parm_index does it for us too. */
3864 tree fixed_up_index =
3865 fixup_template_parm_index (index, arglist, num_parms);
3867 DECL_INITIAL (pushed_decl) = DECL_INITIAL (parm) = fixed_up_index;
3869 /* Add this fixed up PARM to the template parms we've fixed
3870 up so far and use that to substitute the fixed-up
3871 template parms into the type of PARM. */
3872 TREE_VEC_ELT (fixedup_args, idx) =
3873 template_parm_to_arg (parm_desc);
3874 TREE_TYPE (parm) = tsubst (TREE_TYPE (parm), arglist,
3875 tf_none, NULL_TREE);
3878 TREE_PURPOSE (parm_desc) =
3879 tsubst_template_arg (TREE_PURPOSE (parm_desc),
3880 arglist, tf_none, parm);
3882 pop_deferring_access_checks ();
3885 /* Walk the current template parms and properly compute the canonical
3886 types of the dependent types created during
3887 cp_parser_template_parameter_list. */
3890 fixup_template_parms (void)
3897 parameter_vec = INNERMOST_TEMPLATE_PARMS (current_template_parms);
3898 if (parameter_vec == NULL_TREE)
3901 num_parms = TREE_VEC_LENGTH (parameter_vec);
3903 /* This vector contains the current innermost template parms that
3904 have been fixed up so far. The form of FIXEDUP_ARGS is suitable
3905 to be passed to tsubst* functions as their ARGS argument. */
3906 fixedup_args = make_tree_vec (num_parms);
3908 /* This vector contains the full set of template parms in a form
3909 suitable to be passed to substs functions as their ARGS
3911 arglist = current_template_args ();
3912 arglist = add_outermost_template_args (arglist, fixedup_args);
3914 /* Let's do the proper fixup now. */
3915 for (i = 0; i < num_parms; ++i)
3916 fixup_template_parm (TREE_VEC_ELT (parameter_vec, i),
3917 i, num_parms, arglist);
3920 /* end_template_decl is called after a template declaration is seen. */
3923 end_template_decl (void)
3925 reset_specialization ();
3927 if (! processing_template_decl)
3930 /* This matches the pushlevel in begin_template_parm_list. */
3933 --processing_template_decl;
3934 current_template_parms = TREE_CHAIN (current_template_parms);
3937 /* Takes a TREE_LIST representing a template parameter and convert it
3938 into an argument suitable to be passed to the type substitution
3939 functions. Note that If the TREE_LIST contains an error_mark
3940 node, the returned argument is error_mark_node. */
3943 template_parm_to_arg (tree t)
3947 || TREE_CODE (t) != TREE_LIST)
3950 if (error_operand_p (TREE_VALUE (t)))
3951 return error_mark_node;
3955 if (TREE_CODE (t) == TYPE_DECL
3956 || TREE_CODE (t) == TEMPLATE_DECL)
3960 if (TEMPLATE_TYPE_PARAMETER_PACK (t))
3962 /* Turn this argument into a TYPE_ARGUMENT_PACK
3963 with a single element, which expands T. */
3964 tree vec = make_tree_vec (1);
3965 #ifdef ENABLE_CHECKING
3966 SET_NON_DEFAULT_TEMPLATE_ARGS_COUNT
3967 (vec, TREE_VEC_LENGTH (vec));
3969 TREE_VEC_ELT (vec, 0) = make_pack_expansion (t);
3971 t = cxx_make_type (TYPE_ARGUMENT_PACK);
3972 SET_ARGUMENT_PACK_ARGS (t, vec);
3977 t = DECL_INITIAL (t);
3979 if (TEMPLATE_PARM_PARAMETER_PACK (t))
3981 /* Turn this argument into a NONTYPE_ARGUMENT_PACK
3982 with a single element, which expands T. */
3983 tree vec = make_tree_vec (1);
3984 tree type = TREE_TYPE (TEMPLATE_PARM_DECL (t));
3985 #ifdef ENABLE_CHECKING
3986 SET_NON_DEFAULT_TEMPLATE_ARGS_COUNT
3987 (vec, TREE_VEC_LENGTH (vec));
3989 TREE_VEC_ELT (vec, 0) = make_pack_expansion (t);
3991 t = make_node (NONTYPE_ARGUMENT_PACK);
3992 SET_ARGUMENT_PACK_ARGS (t, vec);
3993 TREE_TYPE (t) = type;
3999 /* Within the declaration of a template, return all levels of template
4000 parameters that apply. The template parameters are represented as
4001 a TREE_VEC, in the form documented in cp-tree.h for template
4005 current_template_args (void)
4008 tree args = NULL_TREE;
4009 int length = TMPL_PARMS_DEPTH (current_template_parms);
4012 /* If there is only one level of template parameters, we do not
4013 create a TREE_VEC of TREE_VECs. Instead, we return a single
4014 TREE_VEC containing the arguments. */
4016 args = make_tree_vec (length);
4018 for (header = current_template_parms; header; header = TREE_CHAIN (header))
4020 tree a = copy_node (TREE_VALUE (header));
4023 TREE_TYPE (a) = NULL_TREE;
4024 for (i = TREE_VEC_LENGTH (a) - 1; i >= 0; --i)
4025 TREE_VEC_ELT (a, i) = template_parm_to_arg (TREE_VEC_ELT (a, i));
4027 #ifdef ENABLE_CHECKING
4028 SET_NON_DEFAULT_TEMPLATE_ARGS_COUNT (a, TREE_VEC_LENGTH (a));
4032 TREE_VEC_ELT (args, --l) = a;
4037 if (length > 1 && TREE_VEC_ELT (args, 0) == NULL_TREE)
4038 /* This can happen for template parms of a template template
4041 template<template<class T, class U> class TT> struct S;
4043 Consider the level of the parms of TT; T and U both have
4044 level 2; TT has no template parm of level 1. So in this case
4045 the first element of full_template_args is NULL_TREE. If we
4046 leave it like this TMPL_ARG_DEPTH on args returns 1 instead
4047 of 2. This will make tsubst wrongly consider that T and U
4048 have level 1. Instead, let's create a dummy vector as the
4049 first element of full_template_args so that TMPL_ARG_DEPTH
4050 returns the correct depth for args. */
4051 TREE_VEC_ELT (args, 0) = make_tree_vec (1);
4055 /* Update the declared TYPE by doing any lookups which were thought to be
4056 dependent, but are not now that we know the SCOPE of the declarator. */
4059 maybe_update_decl_type (tree orig_type, tree scope)
4061 tree type = orig_type;
4063 if (type == NULL_TREE)
4066 if (TREE_CODE (orig_type) == TYPE_DECL)
4067 type = TREE_TYPE (type);
4069 if (scope && TYPE_P (scope) && dependent_type_p (scope)
4070 && dependent_type_p (type)
4071 /* Don't bother building up the args in this case. */
4072 && TREE_CODE (type) != TEMPLATE_TYPE_PARM)
4074 /* tsubst in the args corresponding to the template parameters,
4075 including auto if present. Most things will be unchanged, but
4076 make_typename_type and tsubst_qualified_id will resolve
4077 TYPENAME_TYPEs and SCOPE_REFs that were previously dependent. */
4078 tree args = current_template_args ();
4079 tree auto_node = type_uses_auto (type);
4083 tree auto_vec = make_tree_vec (1);
4084 TREE_VEC_ELT (auto_vec, 0) = auto_node;
4085 args = add_to_template_args (args, auto_vec);
4087 pushed = push_scope (scope);
4088 type = tsubst (type, args, tf_warning_or_error, NULL_TREE);
4093 if (type == error_mark_node)
4096 if (TREE_CODE (orig_type) == TYPE_DECL)
4098 if (same_type_p (type, TREE_TYPE (orig_type)))
4101 type = TYPE_NAME (type);
4106 /* Return a TEMPLATE_DECL corresponding to DECL, using the indicated
4107 template PARMS. If MEMBER_TEMPLATE_P is true, the new template is
4108 a member template. Used by push_template_decl below. */
4111 build_template_decl (tree decl, tree parms, bool member_template_p)
4113 tree tmpl = build_lang_decl (TEMPLATE_DECL, DECL_NAME (decl), NULL_TREE);
4114 DECL_TEMPLATE_PARMS (tmpl) = parms;
4115 DECL_CONTEXT (tmpl) = DECL_CONTEXT (decl);
4116 DECL_MEMBER_TEMPLATE_P (tmpl) = member_template_p;
4121 struct template_parm_data
4123 /* The level of the template parameters we are currently
4127 /* The index of the specialization argument we are currently
4131 /* An array whose size is the number of template parameters. The
4132 elements are nonzero if the parameter has been used in any one
4133 of the arguments processed so far. */
4136 /* An array whose size is the number of template arguments. The
4137 elements are nonzero if the argument makes use of template
4138 parameters of this level. */
4139 int* arg_uses_template_parms;
4142 /* Subroutine of push_template_decl used to see if each template
4143 parameter in a partial specialization is used in the explicit
4144 argument list. If T is of the LEVEL given in DATA (which is
4145 treated as a template_parm_data*), then DATA->PARMS is marked
4149 mark_template_parm (tree t, void* data)
4153 struct template_parm_data* tpd = (struct template_parm_data*) data;
4155 if (TREE_CODE (t) == TEMPLATE_PARM_INDEX)
4157 level = TEMPLATE_PARM_LEVEL (t);
4158 idx = TEMPLATE_PARM_IDX (t);
4162 level = TEMPLATE_TYPE_LEVEL (t);
4163 idx = TEMPLATE_TYPE_IDX (t);
4166 if (level == tpd->level)
4168 tpd->parms[idx] = 1;
4169 tpd->arg_uses_template_parms[tpd->current_arg] = 1;
4172 /* Return zero so that for_each_template_parm will continue the
4173 traversal of the tree; we want to mark *every* template parm. */
4177 /* Process the partial specialization DECL. */
4180 process_partial_specialization (tree decl)
4182 tree type = TREE_TYPE (decl);
4183 tree maintmpl = CLASSTYPE_TI_TEMPLATE (type);
4184 tree specargs = CLASSTYPE_TI_ARGS (type);
4185 tree inner_args = INNERMOST_TEMPLATE_ARGS (specargs);
4186 tree main_inner_parms = DECL_INNERMOST_TEMPLATE_PARMS (maintmpl);
4189 int nargs = TREE_VEC_LENGTH (inner_args);
4192 bool did_error_intro = false;
4193 struct template_parm_data tpd;
4194 struct template_parm_data tpd2;
4196 gcc_assert (current_template_parms);
4198 inner_parms = INNERMOST_TEMPLATE_PARMS (current_template_parms);
4199 ntparms = TREE_VEC_LENGTH (inner_parms);
4201 /* We check that each of the template parameters given in the
4202 partial specialization is used in the argument list to the
4203 specialization. For example:
4205 template <class T> struct S;
4206 template <class T> struct S<T*>;
4208 The second declaration is OK because `T*' uses the template
4209 parameter T, whereas
4211 template <class T> struct S<int>;
4213 is no good. Even trickier is:
4224 The S2<T> declaration is actually invalid; it is a
4225 full-specialization. Of course,
4228 struct S2<T (*)(U)>;
4230 or some such would have been OK. */
4231 tpd.level = TMPL_PARMS_DEPTH (current_template_parms);
4232 tpd.parms = XALLOCAVEC (int, ntparms);
4233 memset (tpd.parms, 0, sizeof (int) * ntparms);
4235 tpd.arg_uses_template_parms = XALLOCAVEC (int, nargs);
4236 memset (tpd.arg_uses_template_parms, 0, sizeof (int) * nargs);
4237 for (i = 0; i < nargs; ++i)
4239 tpd.current_arg = i;
4240 for_each_template_parm (TREE_VEC_ELT (inner_args, i),
4241 &mark_template_parm,
4244 /*include_nondeduced_p=*/false);
4246 for (i = 0; i < ntparms; ++i)
4247 if (tpd.parms[i] == 0)
4249 /* One of the template parms was not used in the
4251 if (!did_error_intro)
4253 error ("template parameters not used in partial specialization:");
4254 did_error_intro = true;
4257 error (" %qD", TREE_VALUE (TREE_VEC_ELT (inner_parms, i)));
4260 if (did_error_intro)
4261 return error_mark_node;
4263 /* [temp.class.spec]
4265 The argument list of the specialization shall not be identical to
4266 the implicit argument list of the primary template. */
4267 if (comp_template_args
4269 INNERMOST_TEMPLATE_ARGS (CLASSTYPE_TI_ARGS (TREE_TYPE
4271 error ("partial specialization %qT does not specialize any template arguments", type);
4273 /* [temp.class.spec]
4275 A partially specialized non-type argument expression shall not
4276 involve template parameters of the partial specialization except
4277 when the argument expression is a simple identifier.
4279 The type of a template parameter corresponding to a specialized
4280 non-type argument shall not be dependent on a parameter of the
4283 Also, we verify that pack expansions only occur at the
4284 end of the argument list. */
4285 gcc_assert (nargs == DECL_NTPARMS (maintmpl));
4287 for (i = 0; i < nargs; ++i)
4289 tree parm = TREE_VALUE (TREE_VEC_ELT (main_inner_parms, i));
4290 tree arg = TREE_VEC_ELT (inner_args, i);
4291 tree packed_args = NULL_TREE;
4294 if (ARGUMENT_PACK_P (arg))
4296 /* Extract the arguments from the argument pack. We'll be
4297 iterating over these in the following loop. */
4298 packed_args = ARGUMENT_PACK_ARGS (arg);
4299 len = TREE_VEC_LENGTH (packed_args);
4302 for (j = 0; j < len; j++)
4305 /* Get the Jth argument in the parameter pack. */
4306 arg = TREE_VEC_ELT (packed_args, j);
4308 if (PACK_EXPANSION_P (arg))
4310 /* Pack expansions must come at the end of the
4312 if ((packed_args && j < len - 1)
4313 || (!packed_args && i < nargs - 1))
4315 if (TREE_CODE (arg) == EXPR_PACK_EXPANSION)
4316 error ("parameter pack argument %qE must be at the "
4317 "end of the template argument list", arg);
4319 error ("parameter pack argument %qT must be at the "
4320 "end of the template argument list", arg);
4324 if (TREE_CODE (arg) == EXPR_PACK_EXPANSION)
4325 /* We only care about the pattern. */
4326 arg = PACK_EXPANSION_PATTERN (arg);
4328 if (/* These first two lines are the `non-type' bit. */
4330 && TREE_CODE (arg) != TEMPLATE_DECL
4331 /* This next line is the `argument expression is not just a
4332 simple identifier' condition and also the `specialized
4333 non-type argument' bit. */
4334 && TREE_CODE (arg) != TEMPLATE_PARM_INDEX)
4336 if ((!packed_args && tpd.arg_uses_template_parms[i])
4337 || (packed_args && uses_template_parms (arg)))
4338 error ("template argument %qE involves template parameter(s)",
4342 /* Look at the corresponding template parameter,
4343 marking which template parameters its type depends
4345 tree type = TREE_TYPE (parm);
4349 /* We haven't yet initialized TPD2. Do so now. */
4350 tpd2.arg_uses_template_parms = XALLOCAVEC (int, nargs);
4351 /* The number of parameters here is the number in the
4352 main template, which, as checked in the assertion
4354 tpd2.parms = XALLOCAVEC (int, nargs);
4356 TMPL_PARMS_DEPTH (DECL_TEMPLATE_PARMS (maintmpl));
4359 /* Mark the template parameters. But this time, we're
4360 looking for the template parameters of the main
4361 template, not in the specialization. */
4362 tpd2.current_arg = i;
4363 tpd2.arg_uses_template_parms[i] = 0;
4364 memset (tpd2.parms, 0, sizeof (int) * nargs);
4365 for_each_template_parm (type,
4366 &mark_template_parm,
4369 /*include_nondeduced_p=*/false);
4371 if (tpd2.arg_uses_template_parms [i])
4373 /* The type depended on some template parameters.
4374 If they are fully specialized in the
4375 specialization, that's OK. */
4378 for (j = 0; j < nargs; ++j)
4379 if (tpd2.parms[j] != 0
4380 && tpd.arg_uses_template_parms [j])
4383 error_n (input_location, count,
4384 "type %qT of template argument %qE depends "
4385 "on a template parameter",
4386 "type %qT of template argument %qE depends "
4387 "on template parameters",
4396 /* We should only get here once. */
4397 gcc_assert (!COMPLETE_TYPE_P (type));
4399 DECL_TEMPLATE_SPECIALIZATIONS (maintmpl)
4400 = tree_cons (specargs, inner_parms,
4401 DECL_TEMPLATE_SPECIALIZATIONS (maintmpl));
4402 TREE_TYPE (DECL_TEMPLATE_SPECIALIZATIONS (maintmpl)) = type;
4404 for (inst = DECL_TEMPLATE_INSTANTIATIONS (maintmpl); inst;
4405 inst = TREE_CHAIN (inst))
4407 tree inst_type = TREE_VALUE (inst);
4408 if (COMPLETE_TYPE_P (inst_type)
4409 && CLASSTYPE_IMPLICIT_INSTANTIATION (inst_type))
4411 tree spec = most_specialized_class (inst_type, maintmpl, tf_none);
4412 if (spec && TREE_TYPE (spec) == type)
4413 permerror (input_location,
4414 "partial specialization of %qT after instantiation "
4415 "of %qT", type, inst_type);
4422 /* Check that a template declaration's use of default arguments and
4423 parameter packs is not invalid. Here, PARMS are the template
4424 parameters. IS_PRIMARY is nonzero if DECL is the thing declared by
4425 a primary template. IS_PARTIAL is nonzero if DECL is a partial
4429 IS_FRIEND_DECL is nonzero if DECL is a friend function template
4430 declaration (but not a definition); 1 indicates a declaration, 2
4431 indicates a redeclaration. When IS_FRIEND_DECL=2, no errors are
4432 emitted for extraneous default arguments.
4434 Returns TRUE if there were no errors found, FALSE otherwise. */
4437 check_default_tmpl_args (tree decl, tree parms, int is_primary,
4438 int is_partial, int is_friend_decl)
4441 int last_level_to_check;
4443 bool no_errors = true;
4447 A default template-argument shall not be specified in a
4448 function template declaration or a function template definition, nor
4449 in the template-parameter-list of the definition of a member of a
4452 if (TREE_CODE (CP_DECL_CONTEXT (decl)) == FUNCTION_DECL)
4453 /* You can't have a function template declaration in a local
4454 scope, nor you can you define a member of a class template in a
4458 if (current_class_type
4459 && !TYPE_BEING_DEFINED (current_class_type)
4460 && DECL_LANG_SPECIFIC (decl)
4461 && DECL_DECLARES_FUNCTION_P (decl)
4462 /* If this is either a friend defined in the scope of the class
4463 or a member function. */
4464 && (DECL_FUNCTION_MEMBER_P (decl)
4465 ? same_type_p (DECL_CONTEXT (decl), current_class_type)
4466 : DECL_FRIEND_CONTEXT (decl)
4467 ? same_type_p (DECL_FRIEND_CONTEXT (decl), current_class_type)
4469 /* And, if it was a member function, it really was defined in
4470 the scope of the class. */
4471 && (!DECL_FUNCTION_MEMBER_P (decl)
4472 || DECL_INITIALIZED_IN_CLASS_P (decl)))
4473 /* We already checked these parameters when the template was
4474 declared, so there's no need to do it again now. This function
4475 was defined in class scope, but we're processing it's body now
4476 that the class is complete. */
4479 /* Core issue 226 (C++0x only): the following only applies to class
4481 if ((cxx_dialect == cxx98) || TREE_CODE (decl) != FUNCTION_DECL)
4485 If a template-parameter has a default template-argument, all
4486 subsequent template-parameters shall have a default
4487 template-argument supplied. */
4488 for (parm_level = parms; parm_level; parm_level = TREE_CHAIN (parm_level))
4490 tree inner_parms = TREE_VALUE (parm_level);
4491 int ntparms = TREE_VEC_LENGTH (inner_parms);
4492 int seen_def_arg_p = 0;
4495 for (i = 0; i < ntparms; ++i)
4497 tree parm = TREE_VEC_ELT (inner_parms, i);
4499 if (parm == error_mark_node)
4502 if (TREE_PURPOSE (parm))
4504 else if (seen_def_arg_p
4505 && !template_parameter_pack_p (TREE_VALUE (parm)))
4507 error ("no default argument for %qD", TREE_VALUE (parm));
4508 /* For better subsequent error-recovery, we indicate that
4509 there should have been a default argument. */
4510 TREE_PURPOSE (parm) = error_mark_node;
4516 /* Don't complain about an enclosing partial
4518 && parm_level == parms
4519 && TREE_CODE (decl) == TYPE_DECL
4521 && template_parameter_pack_p (TREE_VALUE (parm)))
4523 /* A primary class template can only have one
4524 parameter pack, at the end of the template
4527 if (TREE_CODE (TREE_VALUE (parm)) == PARM_DECL)
4528 error ("parameter pack %qE must be at the end of the"
4529 " template parameter list", TREE_VALUE (parm));
4531 error ("parameter pack %qT must be at the end of the"
4532 " template parameter list",
4533 TREE_TYPE (TREE_VALUE (parm)));
4535 TREE_VALUE (TREE_VEC_ELT (inner_parms, i))
4543 if (((cxx_dialect == cxx98) && TREE_CODE (decl) != TYPE_DECL)
4547 /* For an ordinary class template, default template arguments are
4548 allowed at the innermost level, e.g.:
4549 template <class T = int>
4551 but, in a partial specialization, they're not allowed even
4552 there, as we have in [temp.class.spec]:
4554 The template parameter list of a specialization shall not
4555 contain default template argument values.
4557 So, for a partial specialization, or for a function template
4558 (in C++98/C++03), we look at all of them. */
4561 /* But, for a primary class template that is not a partial
4562 specialization we look at all template parameters except the
4564 parms = TREE_CHAIN (parms);
4566 /* Figure out what error message to issue. */
4567 if (is_friend_decl == 2)
4568 msg = G_("default template arguments may not be used in function template "
4569 "friend re-declaration");
4570 else if (is_friend_decl)
4571 msg = G_("default template arguments may not be used in function template "
4572 "friend declarations");
4573 else if (TREE_CODE (decl) == FUNCTION_DECL && (cxx_dialect == cxx98))
4574 msg = G_("default template arguments may not be used in function templates "
4575 "without -std=c++0x or -std=gnu++0x");
4576 else if (is_partial)
4577 msg = G_("default template arguments may not be used in "
4578 "partial specializations");
4580 msg = G_("default argument for template parameter for class enclosing %qD");
4582 if (current_class_type && TYPE_BEING_DEFINED (current_class_type))
4583 /* If we're inside a class definition, there's no need to
4584 examine the parameters to the class itself. On the one
4585 hand, they will be checked when the class is defined, and,
4586 on the other, default arguments are valid in things like:
4587 template <class T = double>
4588 struct S { template <class U> void f(U); };
4589 Here the default argument for `S' has no bearing on the
4590 declaration of `f'. */
4591 last_level_to_check = template_class_depth (current_class_type) + 1;
4593 /* Check everything. */
4594 last_level_to_check = 0;
4596 for (parm_level = parms;
4597 parm_level && TMPL_PARMS_DEPTH (parm_level) >= last_level_to_check;
4598 parm_level = TREE_CHAIN (parm_level))
4600 tree inner_parms = TREE_VALUE (parm_level);
4604 ntparms = TREE_VEC_LENGTH (inner_parms);
4605 for (i = 0; i < ntparms; ++i)
4607 if (TREE_VEC_ELT (inner_parms, i) == error_mark_node)
4610 if (TREE_PURPOSE (TREE_VEC_ELT (inner_parms, i)))
4615 if (is_friend_decl == 2)
4622 /* Clear out the default argument so that we are not
4624 TREE_PURPOSE (TREE_VEC_ELT (inner_parms, i)) = NULL_TREE;
4628 /* At this point, if we're still interested in issuing messages,
4629 they must apply to classes surrounding the object declared. */
4631 msg = G_("default argument for template parameter for class "
4638 /* Worker for push_template_decl_real, called via
4639 for_each_template_parm. DATA is really an int, indicating the
4640 level of the parameters we are interested in. If T is a template
4641 parameter of that level, return nonzero. */
4644 template_parm_this_level_p (tree t, void* data)
4646 int this_level = *(int *)data;
4649 if (TREE_CODE (t) == TEMPLATE_PARM_INDEX)
4650 level = TEMPLATE_PARM_LEVEL (t);
4652 level = TEMPLATE_TYPE_LEVEL (t);
4653 return level == this_level;
4656 /* Creates a TEMPLATE_DECL for the indicated DECL using the template
4657 parameters given by current_template_args, or reuses a
4658 previously existing one, if appropriate. Returns the DECL, or an
4659 equivalent one, if it is replaced via a call to duplicate_decls.
4661 If IS_FRIEND is true, DECL is a friend declaration. */
4664 push_template_decl_real (tree decl, bool is_friend)
4672 int new_template_p = 0;
4673 /* True if the template is a member template, in the sense of
4675 bool member_template_p = false;
4677 if (decl == error_mark_node || !current_template_parms)
4678 return error_mark_node;
4680 /* See if this is a partial specialization. */
4681 is_partial = (DECL_IMPLICIT_TYPEDEF_P (decl)
4682 && TREE_CODE (TREE_TYPE (decl)) != ENUMERAL_TYPE
4683 && CLASSTYPE_TEMPLATE_SPECIALIZATION (TREE_TYPE (decl)));
4685 if (TREE_CODE (decl) == FUNCTION_DECL && DECL_FRIEND_P (decl))
4689 /* For a friend, we want the context of the friend function, not
4690 the type of which it is a friend. */
4691 ctx = CP_DECL_CONTEXT (decl);
4692 else if (CP_DECL_CONTEXT (decl)
4693 && TREE_CODE (CP_DECL_CONTEXT (decl)) != NAMESPACE_DECL)
4694 /* In the case of a virtual function, we want the class in which
4696 ctx = CP_DECL_CONTEXT (decl);
4698 /* Otherwise, if we're currently defining some class, the DECL
4699 is assumed to be a member of the class. */
4700 ctx = current_scope ();
4702 if (ctx && TREE_CODE (ctx) == NAMESPACE_DECL)
4705 if (!DECL_CONTEXT (decl))
4706 DECL_CONTEXT (decl) = FROB_CONTEXT (current_namespace);
4708 /* See if this is a primary template. */
4709 if (is_friend && ctx)
4710 /* A friend template that specifies a class context, i.e.
4711 template <typename T> friend void A<T>::f();
4715 primary = template_parm_scope_p ();
4719 if (DECL_CLASS_SCOPE_P (decl))
4720 member_template_p = true;
4721 if (TREE_CODE (decl) == TYPE_DECL
4722 && ANON_AGGRNAME_P (DECL_NAME (decl)))
4724 error ("template class without a name");
4725 return error_mark_node;
4727 else if (TREE_CODE (decl) == FUNCTION_DECL)
4729 if (DECL_DESTRUCTOR_P (decl))
4733 A destructor shall not be a member template. */
4734 error ("destructor %qD declared as member template", decl);
4735 return error_mark_node;
4737 if (NEW_DELETE_OPNAME_P (DECL_NAME (decl))
4738 && (!prototype_p (TREE_TYPE (decl))
4739 || TYPE_ARG_TYPES (TREE_TYPE (decl)) == void_list_node
4740 || !TREE_CHAIN (TYPE_ARG_TYPES (TREE_TYPE (decl)))
4741 || (TREE_CHAIN (TYPE_ARG_TYPES ((TREE_TYPE (decl))))
4742 == void_list_node)))
4744 /* [basic.stc.dynamic.allocation]
4746 An allocation function can be a function
4747 template. ... Template allocation functions shall
4748 have two or more parameters. */
4749 error ("invalid template declaration of %qD", decl);
4750 return error_mark_node;
4753 else if (DECL_IMPLICIT_TYPEDEF_P (decl)
4754 && CLASS_TYPE_P (TREE_TYPE (decl)))
4758 error ("template declaration of %q#D", decl);
4759 return error_mark_node;
4763 /* Check to see that the rules regarding the use of default
4764 arguments are not being violated. */
4765 check_default_tmpl_args (decl, current_template_parms,
4766 primary, is_partial, /*is_friend_decl=*/0);
4768 /* Ensure that there are no parameter packs in the type of this
4769 declaration that have not been expanded. */
4770 if (TREE_CODE (decl) == FUNCTION_DECL)
4772 /* Check each of the arguments individually to see if there are
4773 any bare parameter packs. */
4774 tree type = TREE_TYPE (decl);
4775 tree arg = DECL_ARGUMENTS (decl);
4776 tree argtype = TYPE_ARG_TYPES (type);
4778 while (arg && argtype)
4780 if (!FUNCTION_PARAMETER_PACK_P (arg)
4781 && check_for_bare_parameter_packs (TREE_TYPE (arg)))
4783 /* This is a PARM_DECL that contains unexpanded parameter
4784 packs. We have already complained about this in the
4785 check_for_bare_parameter_packs call, so just replace
4786 these types with ERROR_MARK_NODE. */
4787 TREE_TYPE (arg) = error_mark_node;
4788 TREE_VALUE (argtype) = error_mark_node;
4791 arg = DECL_CHAIN (arg);
4792 argtype = TREE_CHAIN (argtype);
4795 /* Check for bare parameter packs in the return type and the
4796 exception specifiers. */
4797 if (check_for_bare_parameter_packs (TREE_TYPE (type)))
4798 /* Errors were already issued, set return type to int
4799 as the frontend doesn't expect error_mark_node as
4801 TREE_TYPE (type) = integer_type_node;
4802 if (check_for_bare_parameter_packs (TYPE_RAISES_EXCEPTIONS (type)))
4803 TYPE_RAISES_EXCEPTIONS (type) = NULL_TREE;
4805 else if (check_for_bare_parameter_packs (TREE_TYPE (decl)))
4807 TREE_TYPE (decl) = error_mark_node;
4808 return error_mark_node;
4812 return process_partial_specialization (decl);
4814 args = current_template_args ();
4817 || TREE_CODE (ctx) == FUNCTION_DECL
4818 || (CLASS_TYPE_P (ctx) && TYPE_BEING_DEFINED (ctx))
4819 || (is_friend && !DECL_TEMPLATE_INFO (decl)))
4821 if (DECL_LANG_SPECIFIC (decl)
4822 && DECL_TEMPLATE_INFO (decl)
4823 && DECL_TI_TEMPLATE (decl))
4824 tmpl = DECL_TI_TEMPLATE (decl);
4825 /* If DECL is a TYPE_DECL for a class-template, then there won't
4826 be DECL_LANG_SPECIFIC. The information equivalent to
4827 DECL_TEMPLATE_INFO is found in TYPE_TEMPLATE_INFO instead. */
4828 else if (DECL_IMPLICIT_TYPEDEF_P (decl)
4829 && TYPE_TEMPLATE_INFO (TREE_TYPE (decl))
4830 && TYPE_TI_TEMPLATE (TREE_TYPE (decl)))
4832 /* Since a template declaration already existed for this
4833 class-type, we must be redeclaring it here. Make sure
4834 that the redeclaration is valid. */
4835 redeclare_class_template (TREE_TYPE (decl),
4836 current_template_parms);
4837 /* We don't need to create a new TEMPLATE_DECL; just use the
4838 one we already had. */
4839 tmpl = TYPE_TI_TEMPLATE (TREE_TYPE (decl));
4843 tmpl = build_template_decl (decl, current_template_parms,
4847 if (DECL_LANG_SPECIFIC (decl)
4848 && DECL_TEMPLATE_SPECIALIZATION (decl))
4850 /* A specialization of a member template of a template
4852 SET_DECL_TEMPLATE_SPECIALIZATION (tmpl);
4853 DECL_TEMPLATE_INFO (tmpl) = DECL_TEMPLATE_INFO (decl);
4854 DECL_TEMPLATE_INFO (decl) = NULL_TREE;
4860 tree a, t, current, parms;
4862 tree tinfo = get_template_info (decl);
4866 error ("template definition of non-template %q#D", decl);
4867 return error_mark_node;
4870 tmpl = TI_TEMPLATE (tinfo);
4872 if (DECL_FUNCTION_TEMPLATE_P (tmpl)
4873 && DECL_TEMPLATE_INFO (decl) && DECL_TI_ARGS (decl)
4874 && DECL_TEMPLATE_SPECIALIZATION (decl)
4875 && DECL_MEMBER_TEMPLATE_P (tmpl))
4879 /* The declaration is a specialization of a member
4880 template, declared outside the class. Therefore, the
4881 innermost template arguments will be NULL, so we
4882 replace them with the arguments determined by the
4883 earlier call to check_explicit_specialization. */
4884 args = DECL_TI_ARGS (decl);
4887 = build_template_decl (decl, current_template_parms,
4889 DECL_TEMPLATE_RESULT (new_tmpl) = decl;
4890 TREE_TYPE (new_tmpl) = TREE_TYPE (decl);
4891 DECL_TI_TEMPLATE (decl) = new_tmpl;
4892 SET_DECL_TEMPLATE_SPECIALIZATION (new_tmpl);
4893 DECL_TEMPLATE_INFO (new_tmpl)
4894 = build_template_info (tmpl, args);
4896 register_specialization (new_tmpl,
4897 most_general_template (tmpl),
4903 /* Make sure the template headers we got make sense. */
4905 parms = DECL_TEMPLATE_PARMS (tmpl);
4906 i = TMPL_PARMS_DEPTH (parms);
4907 if (TMPL_ARGS_DEPTH (args) != i)
4909 error ("expected %d levels of template parms for %q#D, got %d",
4910 i, decl, TMPL_ARGS_DEPTH (args));
4913 for (current = decl; i > 0; --i, parms = TREE_CHAIN (parms))
4915 a = TMPL_ARGS_LEVEL (args, i);
4916 t = INNERMOST_TEMPLATE_PARMS (parms);
4918 if (TREE_VEC_LENGTH (t) != TREE_VEC_LENGTH (a))
4920 if (current == decl)
4921 error ("got %d template parameters for %q#D",
4922 TREE_VEC_LENGTH (a), decl);
4924 error ("got %d template parameters for %q#T",
4925 TREE_VEC_LENGTH (a), current);
4926 error (" but %d required", TREE_VEC_LENGTH (t));
4927 return error_mark_node;
4930 if (current == decl)
4932 else if (current == NULL_TREE)
4933 /* Can happen in erroneous input. */
4936 current = (TYPE_P (current)
4937 ? TYPE_CONTEXT (current)
4938 : DECL_CONTEXT (current));
4941 /* Check that the parms are used in the appropriate qualifying scopes
4942 in the declarator. */
4943 if (!comp_template_args
4945 TI_ARGS (get_template_info (DECL_TEMPLATE_RESULT (tmpl)))))
4948 template arguments to %qD do not match original template %qD",
4949 decl, DECL_TEMPLATE_RESULT (tmpl));
4950 if (!uses_template_parms (TI_ARGS (tinfo)))
4951 inform (input_location, "use template<> for an explicit specialization");
4952 /* Avoid crash in import_export_decl. */
4953 DECL_INTERFACE_KNOWN (decl) = 1;
4954 return error_mark_node;
4958 DECL_TEMPLATE_RESULT (tmpl) = decl;
4959 TREE_TYPE (tmpl) = TREE_TYPE (decl);
4961 /* Push template declarations for global functions and types. Note
4962 that we do not try to push a global template friend declared in a
4963 template class; such a thing may well depend on the template
4964 parameters of the class. */
4965 if (new_template_p && !ctx
4966 && !(is_friend && template_class_depth (current_class_type) > 0))
4968 tmpl = pushdecl_namespace_level (tmpl, is_friend);
4969 if (tmpl == error_mark_node)
4970 return error_mark_node;
4972 /* Hide template friend classes that haven't been declared yet. */
4973 if (is_friend && TREE_CODE (decl) == TYPE_DECL)
4975 DECL_ANTICIPATED (tmpl) = 1;
4976 DECL_FRIEND_P (tmpl) = 1;
4982 tree parms = DECL_TEMPLATE_PARMS (tmpl);
4985 DECL_PRIMARY_TEMPLATE (tmpl) = tmpl;
4986 if (DECL_CONV_FN_P (tmpl))
4988 int depth = TMPL_PARMS_DEPTH (parms);
4990 /* It is a conversion operator. See if the type converted to
4991 depends on innermost template operands. */
4993 if (uses_template_parms_level (TREE_TYPE (TREE_TYPE (tmpl)),
4995 DECL_TEMPLATE_CONV_FN_P (tmpl) = 1;
4998 /* Give template template parms a DECL_CONTEXT of the template
4999 for which they are a parameter. */
5000 parms = INNERMOST_TEMPLATE_PARMS (parms);
5001 for (i = TREE_VEC_LENGTH (parms) - 1; i >= 0; --i)
5003 tree parm = TREE_VALUE (TREE_VEC_ELT (parms, i));
5004 if (TREE_CODE (parm) == TEMPLATE_DECL)
5005 DECL_CONTEXT (parm) = tmpl;
5009 /* The DECL_TI_ARGS of DECL contains full set of arguments referring
5010 back to its most general template. If TMPL is a specialization,
5011 ARGS may only have the innermost set of arguments. Add the missing
5012 argument levels if necessary. */
5013 if (DECL_TEMPLATE_INFO (tmpl))
5014 args = add_outermost_template_args (DECL_TI_ARGS (tmpl), args);
5016 info = build_template_info (tmpl, args);
5018 if (DECL_IMPLICIT_TYPEDEF_P (decl))
5019 SET_TYPE_TEMPLATE_INFO (TREE_TYPE (tmpl), info);
5020 else if (DECL_LANG_SPECIFIC (decl))
5021 DECL_TEMPLATE_INFO (decl) = info;
5023 return DECL_TEMPLATE_RESULT (tmpl);
5027 push_template_decl (tree decl)
5029 return push_template_decl_real (decl, false);
5032 /* Called when a class template TYPE is redeclared with the indicated
5033 template PARMS, e.g.:
5035 template <class T> struct S;
5036 template <class T> struct S {}; */
5039 redeclare_class_template (tree type, tree parms)
5045 if (!TYPE_TEMPLATE_INFO (type))
5047 error ("%qT is not a template type", type);
5051 tmpl = TYPE_TI_TEMPLATE (type);
5052 if (!PRIMARY_TEMPLATE_P (tmpl))
5053 /* The type is nested in some template class. Nothing to worry
5054 about here; there are no new template parameters for the nested
5060 error ("template specifiers not specified in declaration of %qD",
5065 parms = INNERMOST_TEMPLATE_PARMS (parms);
5066 tmpl_parms = DECL_INNERMOST_TEMPLATE_PARMS (tmpl);
5068 if (TREE_VEC_LENGTH (parms) != TREE_VEC_LENGTH (tmpl_parms))
5070 error_n (input_location, TREE_VEC_LENGTH (parms),
5071 "redeclared with %d template parameter",
5072 "redeclared with %d template parameters",
5073 TREE_VEC_LENGTH (parms));
5074 inform_n (input_location, TREE_VEC_LENGTH (tmpl_parms),
5075 "previous declaration %q+D used %d template parameter",
5076 "previous declaration %q+D used %d template parameters",
5077 tmpl, TREE_VEC_LENGTH (tmpl_parms));
5081 for (i = 0; i < TREE_VEC_LENGTH (tmpl_parms); ++i)
5088 if (TREE_VEC_ELT (tmpl_parms, i) == error_mark_node
5089 || TREE_VEC_ELT (parms, i) == error_mark_node)
5092 tmpl_parm = TREE_VALUE (TREE_VEC_ELT (tmpl_parms, i));
5093 if (tmpl_parm == error_mark_node)
5096 parm = TREE_VALUE (TREE_VEC_ELT (parms, i));
5097 tmpl_default = TREE_PURPOSE (TREE_VEC_ELT (tmpl_parms, i));
5098 parm_default = TREE_PURPOSE (TREE_VEC_ELT (parms, i));
5100 /* TMPL_PARM and PARM can be either TYPE_DECL, PARM_DECL, or
5102 if (TREE_CODE (tmpl_parm) != TREE_CODE (parm)
5103 || (TREE_CODE (tmpl_parm) != TYPE_DECL
5104 && !same_type_p (TREE_TYPE (tmpl_parm), TREE_TYPE (parm)))
5105 || (TREE_CODE (tmpl_parm) != PARM_DECL
5106 && (TEMPLATE_TYPE_PARAMETER_PACK (TREE_TYPE (tmpl_parm))
5107 != TEMPLATE_TYPE_PARAMETER_PACK (TREE_TYPE (parm))))
5108 || (TREE_CODE (tmpl_parm) == PARM_DECL
5109 && (TEMPLATE_PARM_PARAMETER_PACK (DECL_INITIAL (tmpl_parm))
5110 != TEMPLATE_PARM_PARAMETER_PACK (DECL_INITIAL (parm)))))
5112 error ("template parameter %q+#D", tmpl_parm);
5113 error ("redeclared here as %q#D", parm);
5117 if (tmpl_default != NULL_TREE && parm_default != NULL_TREE)
5119 /* We have in [temp.param]:
5121 A template-parameter may not be given default arguments
5122 by two different declarations in the same scope. */
5123 error_at (input_location, "redefinition of default argument for %q#D", parm);
5124 inform (DECL_SOURCE_LOCATION (tmpl_parm),
5125 "original definition appeared here");
5129 if (parm_default != NULL_TREE)
5130 /* Update the previous template parameters (which are the ones
5131 that will really count) with the new default value. */
5132 TREE_PURPOSE (TREE_VEC_ELT (tmpl_parms, i)) = parm_default;
5133 else if (tmpl_default != NULL_TREE)
5134 /* Update the new parameters, too; they'll be used as the
5135 parameters for any members. */
5136 TREE_PURPOSE (TREE_VEC_ELT (parms, i)) = tmpl_default;
5142 /* Simplify EXPR if it is a non-dependent expression. Returns the
5143 (possibly simplified) expression. */
5146 fold_non_dependent_expr_sfinae (tree expr, tsubst_flags_t complain)
5148 if (expr == NULL_TREE)
5151 /* If we're in a template, but EXPR isn't value dependent, simplify
5152 it. We're supposed to treat:
5154 template <typename T> void f(T[1 + 1]);
5155 template <typename T> void f(T[2]);
5157 as two declarations of the same function, for example. */
5158 if (processing_template_decl
5159 && !type_dependent_expression_p (expr)
5160 && potential_constant_expression (expr)
5161 && !value_dependent_expression_p (expr))
5163 HOST_WIDE_INT saved_processing_template_decl;
5165 saved_processing_template_decl = processing_template_decl;
5166 processing_template_decl = 0;
5167 expr = tsubst_copy_and_build (expr,
5170 /*in_decl=*/NULL_TREE,
5171 /*function_p=*/false,
5172 /*integral_constant_expression_p=*/true);
5173 processing_template_decl = saved_processing_template_decl;
5179 fold_non_dependent_expr (tree expr)
5181 return fold_non_dependent_expr_sfinae (expr, tf_error);
5184 /* Subroutine of convert_nontype_argument. Converts EXPR to TYPE, which
5185 must be a function or a pointer-to-function type, as specified
5186 in [temp.arg.nontype]: disambiguate EXPR if it is an overload set,
5187 and check that the resulting function has external linkage. */
5190 convert_nontype_argument_function (tree type, tree expr)
5195 fn = instantiate_type (type, fns, tf_none);
5196 if (fn == error_mark_node)
5197 return error_mark_node;
5200 if (TREE_CODE (fn_no_ptr) == ADDR_EXPR)
5201 fn_no_ptr = TREE_OPERAND (fn_no_ptr, 0);
5202 if (TREE_CODE (fn_no_ptr) == BASELINK)
5203 fn_no_ptr = BASELINK_FUNCTIONS (fn_no_ptr);
5205 /* [temp.arg.nontype]/1
5207 A template-argument for a non-type, non-template template-parameter
5210 -- the address of an object or function with external linkage. */
5211 if (!DECL_EXTERNAL_LINKAGE_P (fn_no_ptr))
5213 error ("%qE is not a valid template argument for type %qT "
5214 "because function %qD has not external linkage",
5215 expr, type, fn_no_ptr);
5222 /* Subroutine of convert_nontype_argument.
5223 Check if EXPR of type TYPE is a valid pointer-to-member constant.
5224 Emit an error otherwise. */
5227 check_valid_ptrmem_cst_expr (tree type, tree expr,
5228 tsubst_flags_t complain)
5231 if (expr && (null_ptr_cst_p (expr) || TREE_CODE (expr) == PTRMEM_CST))
5233 if (complain & tf_error)
5235 error ("%qE is not a valid template argument for type %qT",
5237 error ("it must be a pointer-to-member of the form %<&X::Y%>");
5242 /* Returns TRUE iff the address of OP is value-dependent.
5244 14.6.2.4 [temp.dep.temp]:
5245 A non-integral non-type template-argument is dependent if its type is
5246 dependent or it has either of the following forms
5249 and contains a nested-name-specifier which specifies a class-name that
5250 names a dependent type.
5252 We generalize this to just say that the address of a member of a
5253 dependent class is value-dependent; the above doesn't cover the
5254 address of a static data member named with an unqualified-id. */
5257 has_value_dependent_address (tree op)
5259 /* We could use get_inner_reference here, but there's no need;
5260 this is only relevant for template non-type arguments, which
5261 can only be expressed as &id-expression. */
5264 tree ctx = CP_DECL_CONTEXT (op);
5265 if (TYPE_P (ctx) && dependent_type_p (ctx))
5272 /* Attempt to convert the non-type template parameter EXPR to the
5273 indicated TYPE. If the conversion is successful, return the
5274 converted value. If the conversion is unsuccessful, return
5275 NULL_TREE if we issued an error message, or error_mark_node if we
5276 did not. We issue error messages for out-and-out bad template
5277 parameters, but not simply because the conversion failed, since we
5278 might be just trying to do argument deduction. Both TYPE and EXPR
5279 must be non-dependent.
5281 The conversion follows the special rules described in
5282 [temp.arg.nontype], and it is much more strict than an implicit
5285 This function is called twice for each template argument (see
5286 lookup_template_class for a more accurate description of this
5287 problem). This means that we need to handle expressions which
5288 are not valid in a C++ source, but can be created from the
5289 first call (for instance, casts to perform conversions). These
5290 hacks can go away after we fix the double coercion problem. */
5293 convert_nontype_argument (tree type, tree expr, tsubst_flags_t complain)
5297 /* Detect immediately string literals as invalid non-type argument.
5298 This special-case is not needed for correctness (we would easily
5299 catch this later), but only to provide better diagnostic for this
5300 common user mistake. As suggested by DR 100, we do not mention
5301 linkage issues in the diagnostic as this is not the point. */
5302 /* FIXME we're making this OK. */
5303 if (TREE_CODE (expr) == STRING_CST)
5305 if (complain & tf_error)
5306 error ("%qE is not a valid template argument for type %qT "
5307 "because string literals can never be used in this context",
5312 /* Add the ADDR_EXPR now for the benefit of
5313 value_dependent_expression_p. */
5314 if (TYPE_PTROBV_P (type))
5315 expr = decay_conversion (expr);
5317 /* If we are in a template, EXPR may be non-dependent, but still
5318 have a syntactic, rather than semantic, form. For example, EXPR
5319 might be a SCOPE_REF, rather than the VAR_DECL to which the
5320 SCOPE_REF refers. Preserving the qualifying scope is necessary
5321 so that access checking can be performed when the template is
5322 instantiated -- but here we need the resolved form so that we can
5323 convert the argument. */
5324 if (TYPE_REF_OBJ_P (type)
5325 && has_value_dependent_address (expr))
5326 /* If we want the address and it's value-dependent, don't fold. */;
5327 else if (!type_unknown_p (expr))
5328 expr = fold_non_dependent_expr_sfinae (expr, complain);
5329 if (error_operand_p (expr))
5330 return error_mark_node;
5331 expr_type = TREE_TYPE (expr);
5332 if (TREE_CODE (type) == REFERENCE_TYPE)
5333 expr = mark_lvalue_use (expr);
5335 expr = mark_rvalue_use (expr);
5337 /* HACK: Due to double coercion, we can get a
5338 NOP_EXPR<REFERENCE_TYPE>(ADDR_EXPR<POINTER_TYPE> (arg)) here,
5339 which is the tree that we built on the first call (see
5340 below when coercing to reference to object or to reference to
5341 function). We just strip everything and get to the arg.
5342 See g++.old-deja/g++.oliva/template4.C and g++.dg/template/nontype9.C
5344 if (TREE_CODE (expr) == NOP_EXPR)
5346 if (TYPE_REF_OBJ_P (type) || TYPE_REFFN_P (type))
5348 /* ??? Maybe we could use convert_from_reference here, but we
5349 would need to relax its constraints because the NOP_EXPR
5350 could actually change the type to something more cv-qualified,
5351 and this is not folded by convert_from_reference. */
5352 tree addr = TREE_OPERAND (expr, 0);
5353 gcc_assert (TREE_CODE (expr_type) == REFERENCE_TYPE);
5354 gcc_assert (TREE_CODE (addr) == ADDR_EXPR);
5355 gcc_assert (TREE_CODE (TREE_TYPE (addr)) == POINTER_TYPE);
5356 gcc_assert (same_type_ignoring_top_level_qualifiers_p
5357 (TREE_TYPE (expr_type),
5358 TREE_TYPE (TREE_TYPE (addr))));
5360 expr = TREE_OPERAND (addr, 0);
5361 expr_type = TREE_TYPE (expr);
5364 /* We could also generate a NOP_EXPR(ADDR_EXPR()) when the
5365 parameter is a pointer to object, through decay and
5366 qualification conversion. Let's strip everything. */
5367 else if (TYPE_PTROBV_P (type))
5370 gcc_assert (TREE_CODE (expr) == ADDR_EXPR);
5371 gcc_assert (TREE_CODE (TREE_TYPE (expr)) == POINTER_TYPE);
5372 /* Skip the ADDR_EXPR only if it is part of the decay for
5373 an array. Otherwise, it is part of the original argument
5374 in the source code. */
5375 if (TREE_CODE (TREE_TYPE (TREE_OPERAND (expr, 0))) == ARRAY_TYPE)
5376 expr = TREE_OPERAND (expr, 0);
5377 expr_type = TREE_TYPE (expr);
5381 /* [temp.arg.nontype]/5, bullet 1
5383 For a non-type template-parameter of integral or enumeration type,
5384 integral promotions (_conv.prom_) and integral conversions
5385 (_conv.integral_) are applied. */
5386 if (INTEGRAL_OR_ENUMERATION_TYPE_P (type))
5388 tree t = build_integral_nontype_arg_conv (type, expr, complain);
5389 t = maybe_constant_value (t);
5390 if (t != error_mark_node)
5393 if (!same_type_ignoring_top_level_qualifiers_p (type, TREE_TYPE (expr)))
5394 return error_mark_node;
5396 /* Notice that there are constant expressions like '4 % 0' which
5397 do not fold into integer constants. */
5398 if (TREE_CODE (expr) != INTEGER_CST)
5400 if (complain & tf_error)
5402 error ("%qE is not a valid template argument for type %qT "
5403 "because it is a non-constant expression", expr, type);
5404 cxx_constant_value (expr);
5409 /* [temp.arg.nontype]/5, bullet 2
5411 For a non-type template-parameter of type pointer to object,
5412 qualification conversions (_conv.qual_) and the array-to-pointer
5413 conversion (_conv.array_) are applied. */
5414 else if (TYPE_PTROBV_P (type))
5416 /* [temp.arg.nontype]/1 (TC1 version, DR 49):
5418 A template-argument for a non-type, non-template template-parameter
5419 shall be one of: [...]
5421 -- the name of a non-type template-parameter;
5422 -- the address of an object or function with external linkage, [...]
5423 expressed as "& id-expression" where the & is optional if the name
5424 refers to a function or array, or if the corresponding
5425 template-parameter is a reference.
5427 Here, we do not care about functions, as they are invalid anyway
5428 for a parameter of type pointer-to-object. */
5430 if (DECL_P (expr) && DECL_TEMPLATE_PARM_P (expr))
5431 /* Non-type template parameters are OK. */
5433 else if (TREE_CODE (expr) != ADDR_EXPR
5434 && TREE_CODE (expr_type) != ARRAY_TYPE)
5436 if (TREE_CODE (expr) == VAR_DECL)
5438 error ("%qD is not a valid template argument "
5439 "because %qD is a variable, not the address of "
5444 /* Other values, like integer constants, might be valid
5445 non-type arguments of some other type. */
5446 return error_mark_node;
5452 decl = ((TREE_CODE (expr) == ADDR_EXPR)
5453 ? TREE_OPERAND (expr, 0) : expr);
5454 if (TREE_CODE (decl) != VAR_DECL)
5456 error ("%qE is not a valid template argument of type %qT "
5457 "because %qE is not a variable",
5461 else if (!DECL_EXTERNAL_LINKAGE_P (decl))
5463 error ("%qE is not a valid template argument of type %qT "
5464 "because %qD does not have external linkage",
5470 expr = decay_conversion (expr);
5471 if (expr == error_mark_node)
5472 return error_mark_node;
5474 expr = perform_qualification_conversions (type, expr);
5475 if (expr == error_mark_node)
5476 return error_mark_node;
5478 /* [temp.arg.nontype]/5, bullet 3
5480 For a non-type template-parameter of type reference to object, no
5481 conversions apply. The type referred to by the reference may be more
5482 cv-qualified than the (otherwise identical) type of the
5483 template-argument. The template-parameter is bound directly to the
5484 template-argument, which must be an lvalue. */
5485 else if (TYPE_REF_OBJ_P (type))
5487 if (!same_type_ignoring_top_level_qualifiers_p (TREE_TYPE (type),
5489 return error_mark_node;
5491 if (!at_least_as_qualified_p (TREE_TYPE (type), expr_type))
5493 error ("%qE is not a valid template argument for type %qT "
5494 "because of conflicts in cv-qualification", expr, type);
5498 if (!real_lvalue_p (expr))
5500 error ("%qE is not a valid template argument for type %qT "
5501 "because it is not an lvalue", expr, type);
5505 /* [temp.arg.nontype]/1
5507 A template-argument for a non-type, non-template template-parameter
5508 shall be one of: [...]
5510 -- the address of an object or function with external linkage. */
5511 if (TREE_CODE (expr) == INDIRECT_REF
5512 && TYPE_REF_OBJ_P (TREE_TYPE (TREE_OPERAND (expr, 0))))
5514 expr = TREE_OPERAND (expr, 0);
5517 error ("%q#D is not a valid template argument for type %qT "
5518 "because a reference variable does not have a constant "
5519 "address", expr, type);
5526 error ("%qE is not a valid template argument for type %qT "
5527 "because it is not an object with external linkage",
5532 if (!DECL_EXTERNAL_LINKAGE_P (expr))
5534 error ("%qE is not a valid template argument for type %qT "
5535 "because object %qD has not external linkage",
5540 expr = build_nop (type, build_address (expr));
5542 /* [temp.arg.nontype]/5, bullet 4
5544 For a non-type template-parameter of type pointer to function, only
5545 the function-to-pointer conversion (_conv.func_) is applied. If the
5546 template-argument represents a set of overloaded functions (or a
5547 pointer to such), the matching function is selected from the set
5549 else if (TYPE_PTRFN_P (type))
5551 /* If the argument is a template-id, we might not have enough
5552 context information to decay the pointer. */
5553 if (!type_unknown_p (expr_type))
5555 expr = decay_conversion (expr);
5556 if (expr == error_mark_node)
5557 return error_mark_node;
5560 expr = convert_nontype_argument_function (type, expr);
5561 if (!expr || expr == error_mark_node)
5564 if (TREE_CODE (expr) != ADDR_EXPR)
5566 error ("%qE is not a valid template argument for type %qT", expr, type);
5567 error ("it must be the address of a function with external linkage");
5571 /* [temp.arg.nontype]/5, bullet 5
5573 For a non-type template-parameter of type reference to function, no
5574 conversions apply. If the template-argument represents a set of
5575 overloaded functions, the matching function is selected from the set
5577 else if (TYPE_REFFN_P (type))
5579 if (TREE_CODE (expr) == ADDR_EXPR)
5581 error ("%qE is not a valid template argument for type %qT "
5582 "because it is a pointer", expr, type);
5583 inform (input_location, "try using %qE instead", TREE_OPERAND (expr, 0));
5587 expr = convert_nontype_argument_function (TREE_TYPE (type), expr);
5588 if (!expr || expr == error_mark_node)
5591 expr = build_nop (type, build_address (expr));
5593 /* [temp.arg.nontype]/5, bullet 6
5595 For a non-type template-parameter of type pointer to member function,
5596 no conversions apply. If the template-argument represents a set of
5597 overloaded member functions, the matching member function is selected
5598 from the set (_over.over_). */
5599 else if (TYPE_PTRMEMFUNC_P (type))
5601 expr = instantiate_type (type, expr, tf_none);
5602 if (expr == error_mark_node)
5603 return error_mark_node;
5605 /* [temp.arg.nontype] bullet 1 says the pointer to member
5606 expression must be a pointer-to-member constant. */
5607 if (!check_valid_ptrmem_cst_expr (type, expr, complain))
5608 return error_mark_node;
5610 /* There is no way to disable standard conversions in
5611 resolve_address_of_overloaded_function (called by
5612 instantiate_type). It is possible that the call succeeded by
5613 converting &B::I to &D::I (where B is a base of D), so we need
5614 to reject this conversion here.
5616 Actually, even if there was a way to disable standard conversions,
5617 it would still be better to reject them here so that we can
5618 provide a superior diagnostic. */
5619 if (!same_type_p (TREE_TYPE (expr), type))
5621 error ("%qE is not a valid template argument for type %qT "
5622 "because it is of type %qT", expr, type,
5624 /* If we are just one standard conversion off, explain. */
5625 if (can_convert (type, TREE_TYPE (expr)))
5626 inform (input_location,
5627 "standard conversions are not allowed in this context");
5631 /* [temp.arg.nontype]/5, bullet 7
5633 For a non-type template-parameter of type pointer to data member,
5634 qualification conversions (_conv.qual_) are applied. */
5635 else if (TYPE_PTRMEM_P (type))
5637 /* [temp.arg.nontype] bullet 1 says the pointer to member
5638 expression must be a pointer-to-member constant. */
5639 if (!check_valid_ptrmem_cst_expr (type, expr, complain))
5640 return error_mark_node;
5642 expr = perform_qualification_conversions (type, expr);
5643 if (expr == error_mark_node)
5646 /* A template non-type parameter must be one of the above. */
5650 /* Sanity check: did we actually convert the argument to the
5652 gcc_assert (same_type_ignoring_top_level_qualifiers_p
5653 (type, TREE_TYPE (expr)));
5657 /* Subroutine of coerce_template_template_parms, which returns 1 if
5658 PARM_PARM and ARG_PARM match using the rule for the template
5659 parameters of template template parameters. Both PARM and ARG are
5660 template parameters; the rest of the arguments are the same as for
5661 coerce_template_template_parms.
5664 coerce_template_template_parm (tree parm,
5666 tsubst_flags_t complain,
5670 if (arg == NULL_TREE || arg == error_mark_node
5671 || parm == NULL_TREE || parm == error_mark_node)
5674 if (TREE_CODE (arg) != TREE_CODE (parm))
5677 switch (TREE_CODE (parm))
5680 /* We encounter instantiations of templates like
5681 template <template <template <class> class> class TT>
5684 tree parmparm = DECL_INNERMOST_TEMPLATE_PARMS (parm);
5685 tree argparm = DECL_INNERMOST_TEMPLATE_PARMS (arg);
5687 if (!coerce_template_template_parms
5688 (parmparm, argparm, complain, in_decl, outer_args))
5694 if (TEMPLATE_TYPE_PARAMETER_PACK (TREE_TYPE (arg))
5695 && !TEMPLATE_TYPE_PARAMETER_PACK (TREE_TYPE (parm)))
5696 /* Argument is a parameter pack but parameter is not. */
5701 /* The tsubst call is used to handle cases such as
5703 template <int> class C {};
5704 template <class T, template <T> class TT> class D {};
5707 i.e. the parameter list of TT depends on earlier parameters. */
5708 if (!uses_template_parms (TREE_TYPE (arg))
5710 (tsubst (TREE_TYPE (parm), outer_args, complain, in_decl),
5714 if (TEMPLATE_PARM_PARAMETER_PACK (DECL_INITIAL (arg))
5715 && !TEMPLATE_PARM_PARAMETER_PACK (DECL_INITIAL (parm)))
5716 /* Argument is a parameter pack but parameter is not. */
5729 /* Return 1 if PARM_PARMS and ARG_PARMS matches using rule for
5730 template template parameters. Both PARM_PARMS and ARG_PARMS are
5731 vectors of TREE_LIST nodes containing TYPE_DECL, TEMPLATE_DECL
5734 Consider the example:
5735 template <class T> class A;
5736 template<template <class U> class TT> class B;
5738 For B<A>, PARM_PARMS are the parameters to TT, while ARG_PARMS are
5739 the parameters to A, and OUTER_ARGS contains A. */
5742 coerce_template_template_parms (tree parm_parms,
5744 tsubst_flags_t complain,
5748 int nparms, nargs, i;
5752 gcc_assert (TREE_CODE (parm_parms) == TREE_VEC);
5753 gcc_assert (TREE_CODE (arg_parms) == TREE_VEC);
5755 nparms = TREE_VEC_LENGTH (parm_parms);
5756 nargs = TREE_VEC_LENGTH (arg_parms);
5758 /* Determine whether we have a parameter pack at the end of the
5759 template template parameter's template parameter list. */
5760 if (TREE_VEC_ELT (parm_parms, nparms - 1) != error_mark_node)
5762 parm = TREE_VALUE (TREE_VEC_ELT (parm_parms, nparms - 1));
5764 if (parm == error_mark_node)
5767 switch (TREE_CODE (parm))
5771 if (TEMPLATE_TYPE_PARAMETER_PACK (TREE_TYPE (parm)))
5776 if (TEMPLATE_PARM_PARAMETER_PACK (DECL_INITIAL (parm)))
5786 && !(variadic_p && nargs >= nparms - 1))
5789 /* Check all of the template parameters except the parameter pack at
5790 the end (if any). */
5791 for (i = 0; i < nparms - variadic_p; ++i)
5793 if (TREE_VEC_ELT (parm_parms, i) == error_mark_node
5794 || TREE_VEC_ELT (arg_parms, i) == error_mark_node)
5797 parm = TREE_VALUE (TREE_VEC_ELT (parm_parms, i));
5798 arg = TREE_VALUE (TREE_VEC_ELT (arg_parms, i));
5800 if (!coerce_template_template_parm (parm, arg, complain, in_decl,
5808 /* Check each of the template parameters in the template
5809 argument against the template parameter pack at the end of
5810 the template template parameter. */
5811 if (TREE_VEC_ELT (parm_parms, i) == error_mark_node)
5814 parm = TREE_VALUE (TREE_VEC_ELT (parm_parms, i));
5816 for (; i < nargs; ++i)
5818 if (TREE_VEC_ELT (arg_parms, i) == error_mark_node)
5821 arg = TREE_VALUE (TREE_VEC_ELT (arg_parms, i));
5823 if (!coerce_template_template_parm (parm, arg, complain, in_decl,
5832 /* Verifies that the deduced template arguments (in TARGS) for the
5833 template template parameters (in TPARMS) represent valid bindings,
5834 by comparing the template parameter list of each template argument
5835 to the template parameter list of its corresponding template
5836 template parameter, in accordance with DR150. This
5837 routine can only be called after all template arguments have been
5838 deduced. It will return TRUE if all of the template template
5839 parameter bindings are okay, FALSE otherwise. */
5841 template_template_parm_bindings_ok_p (tree tparms, tree targs)
5843 int i, ntparms = TREE_VEC_LENGTH (tparms);
5846 /* We're dealing with template parms in this process. */
5847 ++processing_template_decl;
5849 targs = INNERMOST_TEMPLATE_ARGS (targs);
5851 for (i = 0; i < ntparms; ++i)
5853 tree tparm = TREE_VALUE (TREE_VEC_ELT (tparms, i));
5854 tree targ = TREE_VEC_ELT (targs, i);
5856 if (TREE_CODE (tparm) == TEMPLATE_DECL && targ)
5858 tree packed_args = NULL_TREE;
5861 if (ARGUMENT_PACK_P (targ))
5863 /* Look inside the argument pack. */
5864 packed_args = ARGUMENT_PACK_ARGS (targ);
5865 len = TREE_VEC_LENGTH (packed_args);
5868 for (idx = 0; idx < len; ++idx)
5870 tree targ_parms = NULL_TREE;
5873 /* Extract the next argument from the argument
5875 targ = TREE_VEC_ELT (packed_args, idx);
5877 if (PACK_EXPANSION_P (targ))
5878 /* Look at the pattern of the pack expansion. */
5879 targ = PACK_EXPANSION_PATTERN (targ);
5881 /* Extract the template parameters from the template
5883 if (TREE_CODE (targ) == TEMPLATE_DECL)
5884 targ_parms = DECL_INNERMOST_TEMPLATE_PARMS (targ);
5885 else if (TREE_CODE (targ) == TEMPLATE_TEMPLATE_PARM)
5886 targ_parms = DECL_INNERMOST_TEMPLATE_PARMS (TYPE_NAME (targ));
5888 /* Verify that we can coerce the template template
5889 parameters from the template argument to the template
5890 parameter. This requires an exact match. */
5892 && !coerce_template_template_parms
5893 (DECL_INNERMOST_TEMPLATE_PARMS (tparm),
5908 --processing_template_decl;
5912 /* Convert the indicated template ARG as necessary to match the
5913 indicated template PARM. Returns the converted ARG, or
5914 error_mark_node if the conversion was unsuccessful. Error and
5915 warning messages are issued under control of COMPLAIN. This
5916 conversion is for the Ith parameter in the parameter list. ARGS is
5917 the full set of template arguments deduced so far. */
5920 convert_template_argument (tree parm,
5923 tsubst_flags_t complain,
5929 int is_type, requires_type, is_tmpl_type, requires_tmpl_type;
5931 if (TREE_CODE (arg) == TREE_LIST
5932 && TREE_CODE (TREE_VALUE (arg)) == OFFSET_REF)
5934 /* The template argument was the name of some
5935 member function. That's usually
5936 invalid, but static members are OK. In any
5937 case, grab the underlying fields/functions
5938 and issue an error later if required. */
5939 orig_arg = TREE_VALUE (arg);
5940 TREE_TYPE (arg) = unknown_type_node;
5945 requires_tmpl_type = TREE_CODE (parm) == TEMPLATE_DECL;
5946 requires_type = (TREE_CODE (parm) == TYPE_DECL
5947 || requires_tmpl_type);
5949 /* When determining whether an argument pack expansion is a template,
5950 look at the pattern. */
5951 if (TREE_CODE (arg) == TYPE_PACK_EXPANSION)
5952 arg = PACK_EXPANSION_PATTERN (arg);
5954 /* Deal with an injected-class-name used as a template template arg. */
5955 if (requires_tmpl_type && CLASS_TYPE_P (arg))
5957 tree t = maybe_get_template_decl_from_type_decl (TYPE_NAME (arg));
5958 if (TREE_CODE (t) == TEMPLATE_DECL)
5960 if (complain & tf_warning_or_error)
5961 pedwarn (input_location, OPT_pedantic, "injected-class-name %qD"
5962 " used as template template argument", TYPE_NAME (arg));
5963 else if (flag_pedantic_errors)
5971 ((TREE_CODE (arg) == TEMPLATE_DECL
5972 && TREE_CODE (DECL_TEMPLATE_RESULT (arg)) == TYPE_DECL)
5973 || TREE_CODE (arg) == TEMPLATE_TEMPLATE_PARM
5974 || TREE_CODE (arg) == UNBOUND_CLASS_TEMPLATE);
5977 && (TREE_CODE (arg) == TEMPLATE_TEMPLATE_PARM
5978 || TREE_CODE (arg) == UNBOUND_CLASS_TEMPLATE))
5979 arg = TYPE_STUB_DECL (arg);
5981 is_type = TYPE_P (arg) || is_tmpl_type;
5983 if (requires_type && ! is_type && TREE_CODE (arg) == SCOPE_REF
5984 && TREE_CODE (TREE_OPERAND (arg, 0)) == TEMPLATE_TYPE_PARM)
5986 permerror (input_location, "to refer to a type member of a template parameter, "
5987 "use %<typename %E%>", orig_arg);
5989 orig_arg = make_typename_type (TREE_OPERAND (arg, 0),
5990 TREE_OPERAND (arg, 1),
5992 complain & tf_error);
5996 if (is_type != requires_type)
6000 if (complain & tf_error)
6002 error ("type/value mismatch at argument %d in template "
6003 "parameter list for %qD",
6006 error (" expected a constant of type %qT, got %qT",
6008 (DECL_P (arg) ? DECL_NAME (arg) : orig_arg));
6009 else if (requires_tmpl_type)
6010 error (" expected a class template, got %qE", orig_arg);
6012 error (" expected a type, got %qE", orig_arg);
6015 return error_mark_node;
6017 if (is_tmpl_type ^ requires_tmpl_type)
6019 if (in_decl && (complain & tf_error))
6021 error ("type/value mismatch at argument %d in template "
6022 "parameter list for %qD",
6025 error (" expected a type, got %qT", DECL_NAME (arg));
6027 error (" expected a class template, got %qT", orig_arg);
6029 return error_mark_node;
6034 if (requires_tmpl_type)
6036 if (TREE_CODE (TREE_TYPE (arg)) == UNBOUND_CLASS_TEMPLATE)
6037 /* The number of argument required is not known yet.
6038 Just accept it for now. */
6039 val = TREE_TYPE (arg);
6042 tree parmparm = DECL_INNERMOST_TEMPLATE_PARMS (parm);
6045 argparm = DECL_INNERMOST_TEMPLATE_PARMS (arg);
6047 if (coerce_template_template_parms (parmparm, argparm,
6053 /* TEMPLATE_TEMPLATE_PARM node is preferred over
6055 if (val != error_mark_node)
6057 if (DECL_TEMPLATE_TEMPLATE_PARM_P (val))
6058 val = TREE_TYPE (val);
6059 if (TREE_CODE (orig_arg) == TYPE_PACK_EXPANSION)
6060 val = make_pack_expansion (val);
6065 if (in_decl && (complain & tf_error))
6067 error ("type/value mismatch at argument %d in "
6068 "template parameter list for %qD",
6070 error (" expected a template of type %qD, got %qT",
6074 val = error_mark_node;
6080 /* We only form one instance of each template specialization.
6081 Therefore, if we use a non-canonical variant (i.e., a
6082 typedef), any future messages referring to the type will use
6083 the typedef, which is confusing if those future uses do not
6084 themselves also use the typedef. */
6086 val = strip_typedefs (val);
6090 tree t = tsubst (TREE_TYPE (parm), args, complain, in_decl);
6092 if (invalid_nontype_parm_type_p (t, complain))
6093 return error_mark_node;
6095 if (template_parameter_pack_p (parm) && ARGUMENT_PACK_P (orig_arg))
6097 if (same_type_p (t, TREE_TYPE (orig_arg)))
6101 /* Not sure if this is reachable, but it doesn't hurt
6103 error ("type mismatch in nontype parameter pack");
6104 val = error_mark_node;
6107 else if (!uses_template_parms (orig_arg) && !uses_template_parms (t))
6108 /* We used to call digest_init here. However, digest_init
6109 will report errors, which we don't want when complain
6110 is zero. More importantly, digest_init will try too
6111 hard to convert things: for example, `0' should not be
6112 converted to pointer type at this point according to
6113 the standard. Accepting this is not merely an
6114 extension, since deciding whether or not these
6115 conversions can occur is part of determining which
6116 function template to call, or whether a given explicit
6117 argument specification is valid. */
6118 val = convert_nontype_argument (t, orig_arg, complain);
6122 if (val == NULL_TREE)
6123 val = error_mark_node;
6124 else if (val == error_mark_node && (complain & tf_error))
6125 error ("could not convert template argument %qE to %qT", orig_arg, t);
6127 if (TREE_CODE (val) == SCOPE_REF)
6129 /* Strip typedefs from the SCOPE_REF. */
6130 tree type = strip_typedefs (TREE_TYPE (val));
6131 tree scope = strip_typedefs (TREE_OPERAND (val, 0));
6132 val = build_qualified_name (type, scope, TREE_OPERAND (val, 1),
6133 QUALIFIED_NAME_IS_TEMPLATE (val));
6140 /* Coerces the remaining template arguments in INNER_ARGS (from
6141 ARG_IDX to the end) into the parameter pack at PARM_IDX in PARMS.
6142 Returns the coerced argument pack. PARM_IDX is the position of this
6143 parameter in the template parameter list. ARGS is the original
6144 template argument list. */
6146 coerce_template_parameter_pack (tree parms,
6154 tsubst_flags_t complain)
6156 tree parm = TREE_VEC_ELT (parms, parm_idx);
6157 int nargs = inner_args ? NUM_TMPL_ARGS (inner_args) : 0;
6160 tree packed_types = NULL_TREE;
6162 if (arg_idx > nargs)
6165 packed_args = make_tree_vec (nargs - arg_idx);
6167 if (TREE_CODE (TREE_VALUE (parm)) == PARM_DECL
6168 && uses_parameter_packs (TREE_TYPE (TREE_VALUE (parm))))
6170 /* When the template parameter is a non-type template
6171 parameter pack whose type uses parameter packs, we need
6172 to look at each of the template arguments
6173 separately. Build a vector of the types for these
6174 non-type template parameters in PACKED_TYPES. */
6176 = make_pack_expansion (TREE_TYPE (TREE_VALUE (parm)));
6177 packed_types = tsubst_pack_expansion (expansion, args,
6180 if (packed_types == error_mark_node)
6181 return error_mark_node;
6183 /* Check that we have the right number of arguments. */
6185 && !PACK_EXPANSION_P (TREE_VEC_ELT (inner_args, arg_idx))
6186 && nargs - arg_idx != TREE_VEC_LENGTH (packed_types))
6189 = TREE_VEC_LENGTH (parms) - 1 + TREE_VEC_LENGTH (packed_types);
6190 error ("wrong number of template arguments (%d, should be %d)",
6191 nargs, needed_parms);
6192 return error_mark_node;
6195 /* If we aren't able to check the actual arguments now
6196 (because they haven't been expanded yet), we can at least
6197 verify that all of the types used for the non-type
6198 template parameter pack are, in fact, valid for non-type
6199 template parameters. */
6201 && PACK_EXPANSION_P (TREE_VEC_ELT (inner_args, arg_idx)))
6203 int j, len = TREE_VEC_LENGTH (packed_types);
6204 for (j = 0; j < len; ++j)
6206 tree t = TREE_VEC_ELT (packed_types, j);
6207 if (invalid_nontype_parm_type_p (t, complain))
6208 return error_mark_node;
6213 /* Convert the remaining arguments, which will be a part of the
6214 parameter pack "parm". */
6215 for (; arg_idx < nargs; ++arg_idx)
6217 tree arg = TREE_VEC_ELT (inner_args, arg_idx);
6218 tree actual_parm = TREE_VALUE (parm);
6220 if (packed_types && !PACK_EXPANSION_P (arg))
6222 /* When we have a vector of types (corresponding to the
6223 non-type template parameter pack that uses parameter
6224 packs in its type, as mention above), and the
6225 argument is not an expansion (which expands to a
6226 currently unknown number of arguments), clone the
6227 parm and give it the next type in PACKED_TYPES. */
6228 actual_parm = copy_node (actual_parm);
6229 TREE_TYPE (actual_parm) =
6230 TREE_VEC_ELT (packed_types, arg_idx - parm_idx);
6233 if (arg != error_mark_node)
6234 arg = convert_template_argument (actual_parm,
6235 arg, new_args, complain, parm_idx,
6237 if (arg == error_mark_node)
6239 TREE_VEC_ELT (packed_args, arg_idx - parm_idx) = arg;
6242 if (TREE_CODE (TREE_VALUE (parm)) == TYPE_DECL
6243 || TREE_CODE (TREE_VALUE (parm)) == TEMPLATE_DECL)
6244 argument_pack = cxx_make_type (TYPE_ARGUMENT_PACK);
6247 argument_pack = make_node (NONTYPE_ARGUMENT_PACK);
6248 TREE_TYPE (argument_pack)
6249 = tsubst (TREE_TYPE (TREE_VALUE (parm)), new_args, complain, in_decl);
6250 TREE_CONSTANT (argument_pack) = 1;
6253 SET_ARGUMENT_PACK_ARGS (argument_pack, packed_args);
6254 #ifdef ENABLE_CHECKING
6255 SET_NON_DEFAULT_TEMPLATE_ARGS_COUNT (packed_args,
6256 TREE_VEC_LENGTH (packed_args));
6258 return argument_pack;
6261 /* Convert all template arguments to their appropriate types, and
6262 return a vector containing the innermost resulting template
6263 arguments. If any error occurs, return error_mark_node. Error and
6264 warning messages are issued under control of COMPLAIN.
6266 If REQUIRE_ALL_ARGS is false, argument deduction will be performed
6267 for arguments not specified in ARGS. Otherwise, if
6268 USE_DEFAULT_ARGS is true, default arguments will be used to fill in
6269 unspecified arguments. If REQUIRE_ALL_ARGS is true, but
6270 USE_DEFAULT_ARGS is false, then all arguments must be specified in
6274 coerce_template_parms (tree parms,
6277 tsubst_flags_t complain,
6278 bool require_all_args,
6279 bool use_default_args)
6281 int nparms, nargs, parm_idx, arg_idx, lost = 0;
6284 tree new_inner_args;
6285 int saved_unevaluated_operand;
6286 int saved_inhibit_evaluation_warnings;
6288 /* When used as a boolean value, indicates whether this is a
6289 variadic template parameter list. Since it's an int, we can also
6290 subtract it from nparms to get the number of non-variadic
6294 if (args == error_mark_node)
6295 return error_mark_node;
6297 nparms = TREE_VEC_LENGTH (parms);
6299 /* Determine if there are any parameter packs. */
6300 for (parm_idx = 0; parm_idx < nparms; ++parm_idx)
6302 tree tparm = TREE_VALUE (TREE_VEC_ELT (parms, parm_idx));
6303 if (template_parameter_pack_p (tparm))
6307 inner_args = INNERMOST_TEMPLATE_ARGS (args);
6308 /* If there are 0 or 1 parameter packs, we need to expand any argument
6309 packs so that we can deduce a parameter pack from some non-packed args
6310 followed by an argument pack, as in variadic85.C. If there are more
6311 than that, we need to leave argument packs intact so the arguments are
6312 assigned to the right parameter packs. This should only happen when
6313 dealing with a nested class inside a partial specialization of a class
6314 template, as in variadic92.C. */
6315 if (variadic_p <= 1)
6316 inner_args = expand_template_argument_pack (inner_args);
6318 nargs = inner_args ? NUM_TMPL_ARGS (inner_args) : 0;
6319 if ((nargs > nparms && !variadic_p)
6320 || (nargs < nparms - variadic_p
6322 && (!use_default_args
6323 || (TREE_VEC_ELT (parms, nargs) != error_mark_node
6324 && !TREE_PURPOSE (TREE_VEC_ELT (parms, nargs))))))
6326 if (complain & tf_error)
6331 error ("wrong number of template arguments "
6332 "(%d, should be %d or more)", nargs, nparms);
6335 error ("wrong number of template arguments "
6336 "(%d, should be %d)", nargs, nparms);
6339 error ("provided for %q+D", in_decl);
6342 return error_mark_node;
6345 /* We need to evaluate the template arguments, even though this
6346 template-id may be nested within a "sizeof". */
6347 saved_unevaluated_operand = cp_unevaluated_operand;
6348 cp_unevaluated_operand = 0;
6349 saved_inhibit_evaluation_warnings = c_inhibit_evaluation_warnings;
6350 c_inhibit_evaluation_warnings = 0;
6351 new_inner_args = make_tree_vec (nparms);
6352 new_args = add_outermost_template_args (args, new_inner_args);
6353 for (parm_idx = 0, arg_idx = 0; parm_idx < nparms; parm_idx++, arg_idx++)
6358 /* Get the Ith template parameter. */
6359 parm = TREE_VEC_ELT (parms, parm_idx);
6361 if (parm == error_mark_node)
6363 TREE_VEC_ELT (new_inner_args, arg_idx) = error_mark_node;
6367 /* Calculate the next argument. */
6368 if (arg_idx < nargs)
6369 arg = TREE_VEC_ELT (inner_args, arg_idx);
6373 if (template_parameter_pack_p (TREE_VALUE (parm))
6374 && !(arg && ARGUMENT_PACK_P (arg)))
6376 /* All remaining arguments will be placed in the
6377 template parameter pack PARM. */
6378 arg = coerce_template_parameter_pack (parms, parm_idx, args,
6379 inner_args, arg_idx,
6383 /* Store this argument. */
6384 if (arg == error_mark_node)
6386 TREE_VEC_ELT (new_inner_args, parm_idx) = arg;
6388 /* We are done with all of the arguments. */
6395 if (PACK_EXPANSION_P (arg))
6397 if (complain & tf_error)
6399 /* FIXME this restriction was removed by N2555; see
6401 /* If ARG is a pack expansion, but PARM is not a
6402 template parameter pack (if it were, we would have
6403 handled it above), we're trying to expand into a
6404 fixed-length argument list. */
6405 if (TREE_CODE (arg) == EXPR_PACK_EXPANSION)
6406 sorry ("cannot expand %<%E%> into a fixed-length "
6407 "argument list", arg);
6409 sorry ("cannot expand %<%T%> into a fixed-length "
6410 "argument list", arg);
6415 else if (require_all_args)
6417 /* There must be a default arg in this case. */
6418 arg = tsubst_template_arg (TREE_PURPOSE (parm), new_args,
6420 /* The position of the first default template argument,
6421 is also the number of non-defaulted arguments in NEW_INNER_ARGS.
6423 if (!NON_DEFAULT_TEMPLATE_ARGS_COUNT (new_inner_args))
6424 SET_NON_DEFAULT_TEMPLATE_ARGS_COUNT (new_inner_args, arg_idx);
6429 if (arg == error_mark_node)
6431 if (complain & tf_error)
6432 error ("template argument %d is invalid", arg_idx + 1);
6435 /* This only occurs if there was an error in the template
6436 parameter list itself (which we would already have
6437 reported) that we are trying to recover from, e.g., a class
6438 template with a parameter list such as
6439 template<typename..., typename>. */
6442 arg = convert_template_argument (TREE_VALUE (parm),
6443 arg, new_args, complain,
6446 if (arg == error_mark_node)
6448 TREE_VEC_ELT (new_inner_args, arg_idx) = arg;
6450 cp_unevaluated_operand = saved_unevaluated_operand;
6451 c_inhibit_evaluation_warnings = saved_inhibit_evaluation_warnings;
6454 return error_mark_node;
6456 #ifdef ENABLE_CHECKING
6457 if (!NON_DEFAULT_TEMPLATE_ARGS_COUNT (new_inner_args))
6458 SET_NON_DEFAULT_TEMPLATE_ARGS_COUNT (new_inner_args,
6459 TREE_VEC_LENGTH (new_inner_args));
6462 return new_inner_args;
6465 /* Returns 1 if template args OT and NT are equivalent. */
6468 template_args_equal (tree ot, tree nt)
6473 if (TREE_CODE (nt) == TREE_VEC)
6474 /* For member templates */
6475 return TREE_CODE (ot) == TREE_VEC && comp_template_args (ot, nt);
6476 else if (PACK_EXPANSION_P (ot))
6477 return PACK_EXPANSION_P (nt)
6478 && template_args_equal (PACK_EXPANSION_PATTERN (ot),
6479 PACK_EXPANSION_PATTERN (nt));
6480 else if (ARGUMENT_PACK_P (ot))
6485 if (!ARGUMENT_PACK_P (nt))
6488 opack = ARGUMENT_PACK_ARGS (ot);
6489 npack = ARGUMENT_PACK_ARGS (nt);
6490 len = TREE_VEC_LENGTH (opack);
6491 if (TREE_VEC_LENGTH (npack) != len)
6493 for (i = 0; i < len; ++i)
6494 if (!template_args_equal (TREE_VEC_ELT (opack, i),
6495 TREE_VEC_ELT (npack, i)))
6499 else if (ot && TREE_CODE (ot) == ARGUMENT_PACK_SELECT)
6501 /* We get here probably because we are in the middle of substituting
6502 into the pattern of a pack expansion. In that case the
6503 ARGUMENT_PACK_SELECT temporarily replaces the pack argument we are
6504 interested in. So we want to use the initial pack argument for
6506 ot = ARGUMENT_PACK_SELECT_FROM_PACK (ot);
6507 if (nt && TREE_CODE (nt) == ARGUMENT_PACK_SELECT)
6508 nt = ARGUMENT_PACK_SELECT_FROM_PACK (nt);
6509 return template_args_equal (ot, nt);
6511 else if (TYPE_P (nt))
6512 return TYPE_P (ot) && same_type_p (ot, nt);
6513 else if (TREE_CODE (ot) == TREE_VEC || TYPE_P (ot))
6516 return cp_tree_equal (ot, nt);
6519 /* Returns 1 iff the OLDARGS and NEWARGS are in fact identical sets
6520 of template arguments. Returns 0 otherwise. */
6523 comp_template_args (tree oldargs, tree newargs)
6527 if (TREE_VEC_LENGTH (oldargs) != TREE_VEC_LENGTH (newargs))
6530 for (i = 0; i < TREE_VEC_LENGTH (oldargs); ++i)
6532 tree nt = TREE_VEC_ELT (newargs, i);
6533 tree ot = TREE_VEC_ELT (oldargs, i);
6535 if (! template_args_equal (ot, nt))
6542 add_pending_template (tree d)
6544 tree ti = (TYPE_P (d)
6545 ? CLASSTYPE_TEMPLATE_INFO (d)
6546 : DECL_TEMPLATE_INFO (d));
6547 struct pending_template *pt;
6550 if (TI_PENDING_TEMPLATE_FLAG (ti))
6553 /* We are called both from instantiate_decl, where we've already had a
6554 tinst_level pushed, and instantiate_template, where we haven't.
6556 level = !current_tinst_level || current_tinst_level->decl != d;
6559 push_tinst_level (d);
6561 pt = ggc_alloc_pending_template ();
6563 pt->tinst = current_tinst_level;
6564 if (last_pending_template)
6565 last_pending_template->next = pt;
6567 pending_templates = pt;
6569 last_pending_template = pt;
6571 TI_PENDING_TEMPLATE_FLAG (ti) = 1;
6578 /* Return a TEMPLATE_ID_EXPR corresponding to the indicated FNS and
6579 ARGLIST. Valid choices for FNS are given in the cp-tree.def
6580 documentation for TEMPLATE_ID_EXPR. */
6583 lookup_template_function (tree fns, tree arglist)
6587 if (fns == error_mark_node || arglist == error_mark_node)
6588 return error_mark_node;
6590 gcc_assert (!arglist || TREE_CODE (arglist) == TREE_VEC);
6591 gcc_assert (fns && (is_overloaded_fn (fns)
6592 || TREE_CODE (fns) == IDENTIFIER_NODE));
6594 if (BASELINK_P (fns))
6596 BASELINK_FUNCTIONS (fns) = build2 (TEMPLATE_ID_EXPR,
6598 BASELINK_FUNCTIONS (fns),
6603 type = TREE_TYPE (fns);
6604 if (TREE_CODE (fns) == OVERLOAD || !type)
6605 type = unknown_type_node;
6607 return build2 (TEMPLATE_ID_EXPR, type, fns, arglist);
6610 /* Within the scope of a template class S<T>, the name S gets bound
6611 (in build_self_reference) to a TYPE_DECL for the class, not a
6612 TEMPLATE_DECL. If DECL is a TYPE_DECL for current_class_type,
6613 or one of its enclosing classes, and that type is a template,
6614 return the associated TEMPLATE_DECL. Otherwise, the original
6617 Also handle the case when DECL is a TREE_LIST of ambiguous
6618 injected-class-names from different bases. */
6621 maybe_get_template_decl_from_type_decl (tree decl)
6623 if (decl == NULL_TREE)
6626 /* DR 176: A lookup that finds an injected-class-name (10.2
6627 [class.member.lookup]) can result in an ambiguity in certain cases
6628 (for example, if it is found in more than one base class). If all of
6629 the injected-class-names that are found refer to specializations of
6630 the same class template, and if the name is followed by a
6631 template-argument-list, the reference refers to the class template
6632 itself and not a specialization thereof, and is not ambiguous. */
6633 if (TREE_CODE (decl) == TREE_LIST)
6635 tree t, tmpl = NULL_TREE;
6636 for (t = decl; t; t = TREE_CHAIN (t))
6638 tree elt = maybe_get_template_decl_from_type_decl (TREE_VALUE (t));
6641 else if (tmpl != elt)
6644 if (tmpl && t == NULL_TREE)
6650 return (decl != NULL_TREE
6651 && DECL_SELF_REFERENCE_P (decl)
6652 && CLASSTYPE_TEMPLATE_INFO (TREE_TYPE (decl)))
6653 ? CLASSTYPE_TI_TEMPLATE (TREE_TYPE (decl)) : decl;
6656 /* Given an IDENTIFIER_NODE (type TEMPLATE_DECL) and a chain of
6657 parameters, find the desired type.
6659 D1 is the PTYPENAME terminal, and ARGLIST is the list of arguments.
6661 IN_DECL, if non-NULL, is the template declaration we are trying to
6664 If ENTERING_SCOPE is nonzero, we are about to enter the scope of
6665 the class we are looking up.
6667 Issue error and warning messages under control of COMPLAIN.
6669 If the template class is really a local class in a template
6670 function, then the FUNCTION_CONTEXT is the function in which it is
6673 ??? Note that this function is currently called *twice* for each
6674 template-id: the first time from the parser, while creating the
6675 incomplete type (finish_template_type), and the second type during the
6676 real instantiation (instantiate_template_class). This is surely something
6677 that we want to avoid. It also causes some problems with argument
6678 coercion (see convert_nontype_argument for more information on this). */
6681 lookup_template_class (tree d1,
6686 tsubst_flags_t complain)
6688 tree templ = NULL_TREE, parmlist;
6695 timevar_push (TV_NAME_LOOKUP);
6697 if (TREE_CODE (d1) == IDENTIFIER_NODE)
6699 tree value = innermost_non_namespace_value (d1);
6700 if (value && DECL_TEMPLATE_TEMPLATE_PARM_P (value))
6705 push_decl_namespace (context);
6706 templ = lookup_name (d1);
6707 templ = maybe_get_template_decl_from_type_decl (templ);
6709 pop_decl_namespace ();
6712 context = DECL_CONTEXT (templ);
6714 else if (TREE_CODE (d1) == TYPE_DECL && MAYBE_CLASS_TYPE_P (TREE_TYPE (d1)))
6716 tree type = TREE_TYPE (d1);
6718 /* If we are declaring a constructor, say A<T>::A<T>, we will get
6719 an implicit typename for the second A. Deal with it. */
6720 if (TREE_CODE (type) == TYPENAME_TYPE && TREE_TYPE (type))
6721 type = TREE_TYPE (type);
6723 if (CLASSTYPE_TEMPLATE_INFO (type))
6725 templ = CLASSTYPE_TI_TEMPLATE (type);
6726 d1 = DECL_NAME (templ);
6729 else if (TREE_CODE (d1) == ENUMERAL_TYPE
6730 || (TYPE_P (d1) && MAYBE_CLASS_TYPE_P (d1)))
6732 templ = TYPE_TI_TEMPLATE (d1);
6733 d1 = DECL_NAME (templ);
6735 else if (TREE_CODE (d1) == TEMPLATE_DECL
6736 && DECL_TEMPLATE_RESULT (d1)
6737 && TREE_CODE (DECL_TEMPLATE_RESULT (d1)) == TYPE_DECL)
6740 d1 = DECL_NAME (templ);
6741 context = DECL_CONTEXT (templ);
6744 /* Issue an error message if we didn't find a template. */
6747 if (complain & tf_error)
6748 error ("%qT is not a template", d1);
6749 POP_TIMEVAR_AND_RETURN (TV_NAME_LOOKUP, error_mark_node);
6752 if (TREE_CODE (templ) != TEMPLATE_DECL
6753 /* Make sure it's a user visible template, if it was named by
6755 || ((complain & tf_user) && !DECL_TEMPLATE_PARM_P (templ)
6756 && !PRIMARY_TEMPLATE_P (templ)))
6758 if (complain & tf_error)
6760 error ("non-template type %qT used as a template", d1);
6762 error ("for template declaration %q+D", in_decl);
6764 POP_TIMEVAR_AND_RETURN (TV_NAME_LOOKUP, error_mark_node);
6767 complain &= ~tf_user;
6769 if (DECL_TEMPLATE_TEMPLATE_PARM_P (templ))
6771 /* Create a new TEMPLATE_DECL and TEMPLATE_TEMPLATE_PARM node to store
6772 template arguments */
6778 parmlist = DECL_INNERMOST_TEMPLATE_PARMS (templ);
6780 /* Consider an example where a template template parameter declared as
6782 template <class T, class U = std::allocator<T> > class TT
6784 The template parameter level of T and U are one level larger than
6785 of TT. To proper process the default argument of U, say when an
6786 instantiation `TT<int>' is seen, we need to build the full
6787 arguments containing {int} as the innermost level. Outer levels,
6788 available when not appearing as default template argument, can be
6789 obtained from the arguments of the enclosing template.
6791 Suppose that TT is later substituted with std::vector. The above
6792 instantiation is `TT<int, std::allocator<T> >' with TT at
6793 level 1, and T at level 2, while the template arguments at level 1
6794 becomes {std::vector} and the inner level 2 is {int}. */
6796 outer = DECL_CONTEXT (templ);
6798 outer = TI_ARGS (get_template_info (DECL_TEMPLATE_RESULT (outer)));
6799 else if (current_template_parms)
6800 /* This is an argument of the current template, so we haven't set
6801 DECL_CONTEXT yet. */
6802 outer = current_template_args ();
6805 arglist = add_to_template_args (outer, arglist);
6807 arglist2 = coerce_template_parms (parmlist, arglist, templ,
6809 /*require_all_args=*/true,
6810 /*use_default_args=*/true);
6811 if (arglist2 == error_mark_node
6812 || (!uses_template_parms (arglist2)
6813 && check_instantiated_args (templ, arglist2, complain)))
6814 POP_TIMEVAR_AND_RETURN (TV_NAME_LOOKUP, error_mark_node);
6816 parm = bind_template_template_parm (TREE_TYPE (templ), arglist2);
6817 POP_TIMEVAR_AND_RETURN (TV_NAME_LOOKUP, parm);
6821 tree template_type = TREE_TYPE (templ);
6824 tree found = NULL_TREE;
6827 int is_dependent_type;
6828 int use_partial_inst_tmpl = false;
6830 gen_tmpl = most_general_template (templ);
6831 parmlist = DECL_TEMPLATE_PARMS (gen_tmpl);
6832 parm_depth = TMPL_PARMS_DEPTH (parmlist);
6833 arg_depth = TMPL_ARGS_DEPTH (arglist);
6835 if (arg_depth == 1 && parm_depth > 1)
6837 /* We've been given an incomplete set of template arguments.
6840 template <class T> struct S1 {
6841 template <class U> struct S2 {};
6842 template <class U> struct S2<U*> {};
6845 we will be called with an ARGLIST of `U*', but the
6846 TEMPLATE will be `template <class T> template
6847 <class U> struct S1<T>::S2'. We must fill in the missing
6850 = add_outermost_template_args (TYPE_TI_ARGS (TREE_TYPE (templ)),
6852 arg_depth = TMPL_ARGS_DEPTH (arglist);
6855 /* Now we should have enough arguments. */
6856 gcc_assert (parm_depth == arg_depth);
6858 /* From here on, we're only interested in the most general
6861 /* Calculate the BOUND_ARGS. These will be the args that are
6862 actually tsubst'd into the definition to create the
6866 /* We have multiple levels of arguments to coerce, at once. */
6868 int saved_depth = TMPL_ARGS_DEPTH (arglist);
6870 tree bound_args = make_tree_vec (parm_depth);
6872 for (i = saved_depth,
6873 t = DECL_TEMPLATE_PARMS (gen_tmpl);
6874 i > 0 && t != NULL_TREE;
6875 --i, t = TREE_CHAIN (t))
6878 if (i == saved_depth)
6879 a = coerce_template_parms (TREE_VALUE (t),
6882 /*require_all_args=*/true,
6883 /*use_default_args=*/true);
6885 /* Outer levels should have already been coerced. */
6886 a = TMPL_ARGS_LEVEL (arglist, i);
6888 /* Don't process further if one of the levels fails. */
6889 if (a == error_mark_node)
6891 /* Restore the ARGLIST to its full size. */
6892 TREE_VEC_LENGTH (arglist) = saved_depth;
6893 POP_TIMEVAR_AND_RETURN (TV_NAME_LOOKUP, error_mark_node);
6896 SET_TMPL_ARGS_LEVEL (bound_args, i, a);
6898 /* We temporarily reduce the length of the ARGLIST so
6899 that coerce_template_parms will see only the arguments
6900 corresponding to the template parameters it is
6902 TREE_VEC_LENGTH (arglist)--;
6905 /* Restore the ARGLIST to its full size. */
6906 TREE_VEC_LENGTH (arglist) = saved_depth;
6908 arglist = bound_args;
6912 = coerce_template_parms (INNERMOST_TEMPLATE_PARMS (parmlist),
6913 INNERMOST_TEMPLATE_ARGS (arglist),
6916 /*require_all_args=*/true,
6917 /*use_default_args=*/true);
6919 if (arglist == error_mark_node)
6920 /* We were unable to bind the arguments. */
6921 POP_TIMEVAR_AND_RETURN (TV_NAME_LOOKUP, error_mark_node);
6923 /* In the scope of a template class, explicit references to the
6924 template class refer to the type of the template, not any
6925 instantiation of it. For example, in:
6927 template <class T> class C { void f(C<T>); }
6929 the `C<T>' is just the same as `C'. Outside of the
6930 class, however, such a reference is an instantiation. */
6932 || !PRIMARY_TEMPLATE_P (gen_tmpl)
6933 || currently_open_class (template_type))
6934 /* comp_template_args is expensive, check it last. */
6935 && comp_template_args (TYPE_TI_ARGS (template_type),
6937 POP_TIMEVAR_AND_RETURN (TV_NAME_LOOKUP, template_type);
6939 /* If we already have this specialization, return it. */
6940 elt.tmpl = gen_tmpl;
6942 hash = hash_specialization (&elt);
6943 entry = (spec_entry *) htab_find_with_hash (type_specializations,
6947 POP_TIMEVAR_AND_RETURN (TV_NAME_LOOKUP, entry->spec);
6949 is_dependent_type = uses_template_parms (arglist);
6951 /* If the deduced arguments are invalid, then the binding
6953 if (!is_dependent_type
6954 && check_instantiated_args (gen_tmpl,
6955 INNERMOST_TEMPLATE_ARGS (arglist),
6957 POP_TIMEVAR_AND_RETURN (TV_NAME_LOOKUP, error_mark_node);
6959 if (!is_dependent_type
6960 && !PRIMARY_TEMPLATE_P (gen_tmpl)
6961 && !LAMBDA_TYPE_P (TREE_TYPE (gen_tmpl))
6962 && TREE_CODE (CP_DECL_CONTEXT (gen_tmpl)) == NAMESPACE_DECL)
6964 found = xref_tag_from_type (TREE_TYPE (gen_tmpl),
6965 DECL_NAME (gen_tmpl),
6966 /*tag_scope=*/ts_global);
6967 POP_TIMEVAR_AND_RETURN (TV_NAME_LOOKUP, found);
6970 context = tsubst (DECL_CONTEXT (gen_tmpl), arglist,
6973 context = global_namespace;
6975 /* Create the type. */
6976 if (TREE_CODE (template_type) == ENUMERAL_TYPE)
6978 if (!is_dependent_type)
6980 set_current_access_from_decl (TYPE_NAME (template_type));
6981 t = start_enum (TYPE_IDENTIFIER (template_type), NULL_TREE,
6982 tsubst (ENUM_UNDERLYING_TYPE (template_type),
6983 arglist, complain, in_decl),
6984 SCOPED_ENUM_P (template_type), NULL);
6988 /* We don't want to call start_enum for this type, since
6989 the values for the enumeration constants may involve
6990 template parameters. And, no one should be interested
6991 in the enumeration constants for such a type. */
6992 t = cxx_make_type (ENUMERAL_TYPE);
6993 SET_SCOPED_ENUM_P (t, SCOPED_ENUM_P (template_type));
6995 SET_OPAQUE_ENUM_P (t, OPAQUE_ENUM_P (template_type));
6996 ENUM_FIXED_UNDERLYING_TYPE_P (t)
6997 = ENUM_FIXED_UNDERLYING_TYPE_P (template_type);
7001 t = make_class_type (TREE_CODE (template_type));
7002 CLASSTYPE_DECLARED_CLASS (t)
7003 = CLASSTYPE_DECLARED_CLASS (template_type);
7004 SET_CLASSTYPE_IMPLICIT_INSTANTIATION (t);
7005 TYPE_FOR_JAVA (t) = TYPE_FOR_JAVA (template_type);
7007 /* A local class. Make sure the decl gets registered properly. */
7008 if (context == current_function_decl)
7009 pushtag (DECL_NAME (gen_tmpl), t, /*tag_scope=*/ts_current);
7011 if (comp_template_args (CLASSTYPE_TI_ARGS (template_type), arglist))
7012 /* This instantiation is another name for the primary
7013 template type. Set the TYPE_CANONICAL field
7015 TYPE_CANONICAL (t) = template_type;
7016 else if (any_template_arguments_need_structural_equality_p (arglist))
7017 /* Some of the template arguments require structural
7018 equality testing, so this template class requires
7019 structural equality testing. */
7020 SET_TYPE_STRUCTURAL_EQUALITY (t);
7023 /* If we called start_enum or pushtag above, this information
7024 will already be set up. */
7027 TYPE_CONTEXT (t) = FROB_CONTEXT (context);
7029 type_decl = create_implicit_typedef (DECL_NAME (gen_tmpl), t);
7030 DECL_CONTEXT (type_decl) = TYPE_CONTEXT (t);
7031 DECL_SOURCE_LOCATION (type_decl)
7032 = DECL_SOURCE_LOCATION (TYPE_STUB_DECL (template_type));
7035 type_decl = TYPE_NAME (t);
7037 TREE_PRIVATE (type_decl)
7038 = TREE_PRIVATE (TYPE_STUB_DECL (template_type));
7039 TREE_PROTECTED (type_decl)
7040 = TREE_PROTECTED (TYPE_STUB_DECL (template_type));
7041 if (CLASSTYPE_VISIBILITY_SPECIFIED (template_type))
7043 DECL_VISIBILITY_SPECIFIED (type_decl) = 1;
7044 DECL_VISIBILITY (type_decl) = CLASSTYPE_VISIBILITY (template_type);
7047 /* Let's consider the explicit specialization of a member
7048 of a class template specialization that is implicitely instantiated,
7053 template<class U> struct M {}; //#0
7058 struct S<int>::M<char> //#1
7062 [temp.expl.spec]/4 says this is valid.
7064 In this case, when we write:
7067 M is instantiated from the CLASSTYPE_TI_TEMPLATE of #1, not from
7070 When we encounter #1, we want to store the partial instantiation
7071 of M (template<class T> S<int>::M<T>) in it's CLASSTYPE_TI_TEMPLATE.
7073 For all cases other than this "explicit specialization of member of a
7074 class template", we just want to store the most general template into
7075 the CLASSTYPE_TI_TEMPLATE of M.
7077 This case of "explicit specialization of member of a class template"
7079 1/ the enclosing class is an instantiation of, and therefore not
7080 the same as, the context of the most general template, and
7081 2/ we aren't looking at the partial instantiation itself, i.e.
7082 the innermost arguments are not the same as the innermost parms of
7083 the most general template.
7085 So it's only when 1/ and 2/ happens that we want to use the partial
7086 instantiation of the member template in lieu of its most general
7089 if (PRIMARY_TEMPLATE_P (gen_tmpl)
7090 && TMPL_ARGS_HAVE_MULTIPLE_LEVELS (arglist)
7091 /* the enclosing class must be an instantiation... */
7092 && CLASS_TYPE_P (context)
7093 && !same_type_p (context, DECL_CONTEXT (gen_tmpl)))
7095 tree partial_inst_args;
7096 TREE_VEC_LENGTH (arglist)--;
7097 ++processing_template_decl;
7099 tsubst (INNERMOST_TEMPLATE_ARGS
7100 (CLASSTYPE_TI_ARGS (TREE_TYPE (gen_tmpl))),
7101 arglist, complain, NULL_TREE);
7102 --processing_template_decl;
7103 TREE_VEC_LENGTH (arglist)++;
7104 use_partial_inst_tmpl =
7105 /*...and we must not be looking at the partial instantiation
7107 !comp_template_args (INNERMOST_TEMPLATE_ARGS (arglist),
7111 if (!use_partial_inst_tmpl)
7112 /* This case is easy; there are no member templates involved. */
7116 /* This is a full instantiation of a member template. Find
7117 the partial instantiation of which this is an instance. */
7119 /* Temporarily reduce by one the number of levels in the ARGLIST
7120 so as to avoid comparing the last set of arguments. */
7121 TREE_VEC_LENGTH (arglist)--;
7122 found = tsubst (gen_tmpl, arglist, complain, NULL_TREE);
7123 TREE_VEC_LENGTH (arglist)++;
7124 found = CLASSTYPE_TI_TEMPLATE (found);
7127 SET_TYPE_TEMPLATE_INFO (t, build_template_info (found, arglist));
7130 slot = (spec_entry **) htab_find_slot_with_hash (type_specializations,
7131 &elt, hash, INSERT);
7132 *slot = ggc_alloc_spec_entry ();
7135 /* Note this use of the partial instantiation so we can check it
7136 later in maybe_process_partial_specialization. */
7137 DECL_TEMPLATE_INSTANTIATIONS (templ)
7138 = tree_cons (arglist, t,
7139 DECL_TEMPLATE_INSTANTIATIONS (templ));
7141 if (TREE_CODE (t) == ENUMERAL_TYPE && !is_dependent_type)
7142 /* Now that the type has been registered on the instantiations
7143 list, we set up the enumerators. Because the enumeration
7144 constants may involve the enumeration type itself, we make
7145 sure to register the type first, and then create the
7146 constants. That way, doing tsubst_expr for the enumeration
7147 constants won't result in recursive calls here; we'll find
7148 the instantiation and exit above. */
7149 tsubst_enum (template_type, t, arglist);
7151 if (is_dependent_type)
7152 /* If the type makes use of template parameters, the
7153 code that generates debugging information will crash. */
7154 DECL_IGNORED_P (TYPE_STUB_DECL (t)) = 1;
7156 /* Possibly limit visibility based on template args. */
7157 TREE_PUBLIC (type_decl) = 1;
7158 determine_visibility (type_decl);
7160 POP_TIMEVAR_AND_RETURN (TV_NAME_LOOKUP, t);
7162 timevar_pop (TV_NAME_LOOKUP);
7169 /* True when we should also visit template parameters that occur in
7170 non-deduced contexts. */
7171 bool include_nondeduced_p;
7172 struct pointer_set_t *visited;
7175 /* Called from for_each_template_parm via walk_tree. */
7178 for_each_template_parm_r (tree *tp, int *walk_subtrees, void *d)
7181 struct pair_fn_data *pfd = (struct pair_fn_data *) d;
7182 tree_fn_t fn = pfd->fn;
7183 void *data = pfd->data;
7186 && (pfd->include_nondeduced_p || TREE_CODE (t) != TYPENAME_TYPE)
7187 && for_each_template_parm (TYPE_CONTEXT (t), fn, data, pfd->visited,
7188 pfd->include_nondeduced_p))
7189 return error_mark_node;
7191 switch (TREE_CODE (t))
7194 if (TYPE_PTRMEMFUNC_P (t))
7200 if (!TYPE_TEMPLATE_INFO (t))
7202 else if (for_each_template_parm (TI_ARGS (TYPE_TEMPLATE_INFO (t)),
7203 fn, data, pfd->visited,
7204 pfd->include_nondeduced_p))
7205 return error_mark_node;
7209 if (for_each_template_parm (TYPE_MIN_VALUE (t),
7210 fn, data, pfd->visited,
7211 pfd->include_nondeduced_p)
7212 || for_each_template_parm (TYPE_MAX_VALUE (t),
7213 fn, data, pfd->visited,
7214 pfd->include_nondeduced_p))
7215 return error_mark_node;
7219 /* Since we're not going to walk subtrees, we have to do this
7221 if (for_each_template_parm (TYPE_METHOD_BASETYPE (t), fn, data,
7222 pfd->visited, pfd->include_nondeduced_p))
7223 return error_mark_node;
7227 /* Check the return type. */
7228 if (for_each_template_parm (TREE_TYPE (t), fn, data, pfd->visited,
7229 pfd->include_nondeduced_p))
7230 return error_mark_node;
7232 /* Check the parameter types. Since default arguments are not
7233 instantiated until they are needed, the TYPE_ARG_TYPES may
7234 contain expressions that involve template parameters. But,
7235 no-one should be looking at them yet. And, once they're
7236 instantiated, they don't contain template parameters, so
7237 there's no point in looking at them then, either. */
7241 for (parm = TYPE_ARG_TYPES (t); parm; parm = TREE_CHAIN (parm))
7242 if (for_each_template_parm (TREE_VALUE (parm), fn, data,
7243 pfd->visited, pfd->include_nondeduced_p))
7244 return error_mark_node;
7246 /* Since we've already handled the TYPE_ARG_TYPES, we don't
7247 want walk_tree walking into them itself. */
7253 if (pfd->include_nondeduced_p
7254 && for_each_template_parm (TYPE_FIELDS (t), fn, data,
7256 pfd->include_nondeduced_p))
7257 return error_mark_node;
7262 if (DECL_LANG_SPECIFIC (t) && DECL_TEMPLATE_INFO (t)
7263 && for_each_template_parm (DECL_TI_ARGS (t), fn, data,
7264 pfd->visited, pfd->include_nondeduced_p))
7265 return error_mark_node;
7270 if (TREE_CODE (t) == CONST_DECL && DECL_TEMPLATE_PARM_P (t)
7271 && for_each_template_parm (DECL_INITIAL (t), fn, data,
7272 pfd->visited, pfd->include_nondeduced_p))
7273 return error_mark_node;
7274 if (DECL_CONTEXT (t)
7275 && pfd->include_nondeduced_p
7276 && for_each_template_parm (DECL_CONTEXT (t), fn, data,
7277 pfd->visited, pfd->include_nondeduced_p))
7278 return error_mark_node;
7281 case BOUND_TEMPLATE_TEMPLATE_PARM:
7282 /* Record template parameters such as `T' inside `TT<T>'. */
7283 if (for_each_template_parm (TYPE_TI_ARGS (t), fn, data, pfd->visited,
7284 pfd->include_nondeduced_p))
7285 return error_mark_node;
7288 case TEMPLATE_TEMPLATE_PARM:
7289 case TEMPLATE_TYPE_PARM:
7290 case TEMPLATE_PARM_INDEX:
7291 if (fn && (*fn)(t, data))
7292 return error_mark_node;
7294 return error_mark_node;
7298 /* A template template parameter is encountered. */
7299 if (DECL_TEMPLATE_TEMPLATE_PARM_P (t)
7300 && for_each_template_parm (TREE_TYPE (t), fn, data, pfd->visited,
7301 pfd->include_nondeduced_p))
7302 return error_mark_node;
7304 /* Already substituted template template parameter */
7310 || for_each_template_parm (TYPENAME_TYPE_FULLNAME (t), fn,
7312 pfd->include_nondeduced_p))
7313 return error_mark_node;
7317 if (TREE_TYPE (t) && TYPE_PTRMEMFUNC_P (TREE_TYPE (t))
7318 && pfd->include_nondeduced_p
7319 && for_each_template_parm (TYPE_PTRMEMFUNC_FN_TYPE
7320 (TREE_TYPE (t)), fn, data,
7321 pfd->visited, pfd->include_nondeduced_p))
7322 return error_mark_node;
7327 /* If there's no type, then this thing must be some expression
7328 involving template parameters. */
7329 if (!fn && !TREE_TYPE (t))
7330 return error_mark_node;
7335 case REINTERPRET_CAST_EXPR:
7336 case CONST_CAST_EXPR:
7337 case STATIC_CAST_EXPR:
7338 case DYNAMIC_CAST_EXPR:
7342 case PSEUDO_DTOR_EXPR:
7344 return error_mark_node;
7351 /* We didn't find any template parameters we liked. */
7355 /* For each TEMPLATE_TYPE_PARM, TEMPLATE_TEMPLATE_PARM,
7356 BOUND_TEMPLATE_TEMPLATE_PARM or TEMPLATE_PARM_INDEX in T,
7357 call FN with the parameter and the DATA.
7358 If FN returns nonzero, the iteration is terminated, and
7359 for_each_template_parm returns 1. Otherwise, the iteration
7360 continues. If FN never returns a nonzero value, the value
7361 returned by for_each_template_parm is 0. If FN is NULL, it is
7362 considered to be the function which always returns 1.
7364 If INCLUDE_NONDEDUCED_P, then this routine will also visit template
7365 parameters that occur in non-deduced contexts. When false, only
7366 visits those template parameters that can be deduced. */
7369 for_each_template_parm (tree t, tree_fn_t fn, void* data,
7370 struct pointer_set_t *visited,
7371 bool include_nondeduced_p)
7373 struct pair_fn_data pfd;
7379 pfd.include_nondeduced_p = include_nondeduced_p;
7381 /* Walk the tree. (Conceptually, we would like to walk without
7382 duplicates, but for_each_template_parm_r recursively calls
7383 for_each_template_parm, so we would need to reorganize a fair
7384 bit to use walk_tree_without_duplicates, so we keep our own
7387 pfd.visited = visited;
7389 pfd.visited = pointer_set_create ();
7390 result = cp_walk_tree (&t,
7391 for_each_template_parm_r,
7393 pfd.visited) != NULL_TREE;
7398 pointer_set_destroy (pfd.visited);
7405 /* Returns true if T depends on any template parameter. */
7408 uses_template_parms (tree t)
7411 int saved_processing_template_decl;
7413 saved_processing_template_decl = processing_template_decl;
7414 if (!saved_processing_template_decl)
7415 processing_template_decl = 1;
7417 dependent_p = dependent_type_p (t);
7418 else if (TREE_CODE (t) == TREE_VEC)
7419 dependent_p = any_dependent_template_arguments_p (t);
7420 else if (TREE_CODE (t) == TREE_LIST)
7421 dependent_p = (uses_template_parms (TREE_VALUE (t))
7422 || uses_template_parms (TREE_CHAIN (t)));
7423 else if (TREE_CODE (t) == TYPE_DECL)
7424 dependent_p = dependent_type_p (TREE_TYPE (t));
7427 || TREE_CODE (t) == TEMPLATE_PARM_INDEX
7428 || TREE_CODE (t) == OVERLOAD
7429 || TREE_CODE (t) == BASELINK
7430 || TREE_CODE (t) == IDENTIFIER_NODE
7431 || TREE_CODE (t) == TRAIT_EXPR
7432 || TREE_CODE (t) == CONSTRUCTOR
7433 || CONSTANT_CLASS_P (t))
7434 dependent_p = (type_dependent_expression_p (t)
7435 || value_dependent_expression_p (t));
7438 gcc_assert (t == error_mark_node);
7439 dependent_p = false;
7442 processing_template_decl = saved_processing_template_decl;
7447 /* Returns true if T depends on any template parameter with level LEVEL. */
7450 uses_template_parms_level (tree t, int level)
7452 return for_each_template_parm (t, template_parm_this_level_p, &level, NULL,
7453 /*include_nondeduced_p=*/true);
7456 static int tinst_depth;
7457 extern int max_tinst_depth;
7458 #ifdef GATHER_STATISTICS
7461 static int tinst_level_tick;
7462 static int last_template_error_tick;
7464 /* We're starting to instantiate D; record the template instantiation context
7465 for diagnostics and to restore it later. */
7468 push_tinst_level (tree d)
7470 struct tinst_level *new_level;
7472 if (tinst_depth >= max_tinst_depth)
7474 /* If the instantiation in question still has unbound template parms,
7475 we don't really care if we can't instantiate it, so just return.
7476 This happens with base instantiation for implicit `typename'. */
7477 if (uses_template_parms (d))
7480 last_template_error_tick = tinst_level_tick;
7481 error ("template instantiation depth exceeds maximum of %d (use "
7482 "-ftemplate-depth= to increase the maximum) instantiating %qD",
7483 max_tinst_depth, d);
7485 print_instantiation_context ();
7490 new_level = ggc_alloc_tinst_level ();
7491 new_level->decl = d;
7492 new_level->locus = input_location;
7493 new_level->in_system_header_p = in_system_header;
7494 new_level->next = current_tinst_level;
7495 current_tinst_level = new_level;
7498 #ifdef GATHER_STATISTICS
7499 if (tinst_depth > depth_reached)
7500 depth_reached = tinst_depth;
7507 /* We're done instantiating this template; return to the instantiation
7511 pop_tinst_level (void)
7513 /* Restore the filename and line number stashed away when we started
7514 this instantiation. */
7515 input_location = current_tinst_level->locus;
7516 current_tinst_level = current_tinst_level->next;
7521 /* We're instantiating a deferred template; restore the template
7522 instantiation context in which the instantiation was requested, which
7523 is one step out from LEVEL. Return the corresponding DECL or TYPE. */
7526 reopen_tinst_level (struct tinst_level *level)
7528 struct tinst_level *t;
7531 for (t = level; t; t = t->next)
7534 current_tinst_level = level;
7539 /* Returns the TINST_LEVEL which gives the original instantiation
7542 struct tinst_level *
7543 outermost_tinst_level (void)
7545 struct tinst_level *level = current_tinst_level;
7548 level = level->next;
7552 /* Returns TRUE if PARM is a parameter of the template TEMPL. */
7555 parameter_of_template_p (tree parm, tree templ)
7560 if (!parm || !templ)
7563 gcc_assert (DECL_TEMPLATE_PARM_P (parm));
7564 gcc_assert (TREE_CODE (templ) == TEMPLATE_DECL);
7566 parms = DECL_TEMPLATE_PARMS (templ);
7567 parms = INNERMOST_TEMPLATE_PARMS (parms);
7569 for (i = 0; i < TREE_VEC_LENGTH (parms); ++i)
7570 if (parm == TREE_VALUE (TREE_VEC_ELT (parms, i)))
7576 /* DECL is a friend FUNCTION_DECL or TEMPLATE_DECL. ARGS is the
7577 vector of template arguments, as for tsubst.
7579 Returns an appropriate tsubst'd friend declaration. */
7582 tsubst_friend_function (tree decl, tree args)
7586 if (TREE_CODE (decl) == FUNCTION_DECL
7587 && DECL_TEMPLATE_INSTANTIATION (decl)
7588 && TREE_CODE (DECL_TI_TEMPLATE (decl)) != TEMPLATE_DECL)
7589 /* This was a friend declared with an explicit template
7590 argument list, e.g.:
7594 to indicate that f was a template instantiation, not a new
7595 function declaration. Now, we have to figure out what
7596 instantiation of what template. */
7598 tree template_id, arglist, fns;
7601 tree ns = decl_namespace_context (TYPE_MAIN_DECL (current_class_type));
7603 /* Friend functions are looked up in the containing namespace scope.
7604 We must enter that scope, to avoid finding member functions of the
7605 current class with same name. */
7606 push_nested_namespace (ns);
7607 fns = tsubst_expr (DECL_TI_TEMPLATE (decl), args,
7608 tf_warning_or_error, NULL_TREE,
7609 /*integral_constant_expression_p=*/false);
7610 pop_nested_namespace (ns);
7611 arglist = tsubst (DECL_TI_ARGS (decl), args,
7612 tf_warning_or_error, NULL_TREE);
7613 template_id = lookup_template_function (fns, arglist);
7615 new_friend = tsubst (decl, args, tf_warning_or_error, NULL_TREE);
7616 tmpl = determine_specialization (template_id, new_friend,
7618 /*need_member_template=*/0,
7619 TREE_VEC_LENGTH (args),
7621 return instantiate_template (tmpl, new_args, tf_error);
7624 new_friend = tsubst (decl, args, tf_warning_or_error, NULL_TREE);
7626 /* The NEW_FRIEND will look like an instantiation, to the
7627 compiler, but is not an instantiation from the point of view of
7628 the language. For example, we might have had:
7630 template <class T> struct S {
7631 template <class U> friend void f(T, U);
7634 Then, in S<int>, template <class U> void f(int, U) is not an
7635 instantiation of anything. */
7636 if (new_friend == error_mark_node)
7637 return error_mark_node;
7639 DECL_USE_TEMPLATE (new_friend) = 0;
7640 if (TREE_CODE (decl) == TEMPLATE_DECL)
7642 DECL_USE_TEMPLATE (DECL_TEMPLATE_RESULT (new_friend)) = 0;
7643 DECL_SAVED_TREE (DECL_TEMPLATE_RESULT (new_friend))
7644 = DECL_SAVED_TREE (DECL_TEMPLATE_RESULT (decl));
7647 /* The mangled name for the NEW_FRIEND is incorrect. The function
7648 is not a template instantiation and should not be mangled like
7649 one. Therefore, we forget the mangling here; we'll recompute it
7650 later if we need it. */
7651 if (TREE_CODE (new_friend) != TEMPLATE_DECL)
7653 SET_DECL_RTL (new_friend, NULL);
7654 SET_DECL_ASSEMBLER_NAME (new_friend, NULL_TREE);
7657 if (DECL_NAMESPACE_SCOPE_P (new_friend))
7660 tree new_friend_template_info;
7661 tree new_friend_result_template_info;
7663 int new_friend_is_defn;
7665 /* We must save some information from NEW_FRIEND before calling
7666 duplicate decls since that function will free NEW_FRIEND if
7668 new_friend_template_info = DECL_TEMPLATE_INFO (new_friend);
7669 new_friend_is_defn =
7670 (DECL_INITIAL (DECL_TEMPLATE_RESULT
7671 (template_for_substitution (new_friend)))
7673 if (TREE_CODE (new_friend) == TEMPLATE_DECL)
7675 /* This declaration is a `primary' template. */
7676 DECL_PRIMARY_TEMPLATE (new_friend) = new_friend;
7678 new_friend_result_template_info
7679 = DECL_TEMPLATE_INFO (DECL_TEMPLATE_RESULT (new_friend));
7682 new_friend_result_template_info = NULL_TREE;
7684 /* Make the init_value nonzero so pushdecl knows this is a defn. */
7685 if (new_friend_is_defn)
7686 DECL_INITIAL (new_friend) = error_mark_node;
7688 /* Inside pushdecl_namespace_level, we will push into the
7689 current namespace. However, the friend function should go
7690 into the namespace of the template. */
7691 ns = decl_namespace_context (new_friend);
7692 push_nested_namespace (ns);
7693 old_decl = pushdecl_namespace_level (new_friend, /*is_friend=*/true);
7694 pop_nested_namespace (ns);
7696 if (old_decl == error_mark_node)
7697 return error_mark_node;
7699 if (old_decl != new_friend)
7701 /* This new friend declaration matched an existing
7702 declaration. For example, given:
7704 template <class T> void f(T);
7705 template <class U> class C {
7706 template <class T> friend void f(T) {}
7709 the friend declaration actually provides the definition
7710 of `f', once C has been instantiated for some type. So,
7711 old_decl will be the out-of-class template declaration,
7712 while new_friend is the in-class definition.
7714 But, if `f' was called before this point, the
7715 instantiation of `f' will have DECL_TI_ARGS corresponding
7716 to `T' but not to `U', references to which might appear
7717 in the definition of `f'. Previously, the most general
7718 template for an instantiation of `f' was the out-of-class
7719 version; now it is the in-class version. Therefore, we
7720 run through all specialization of `f', adding to their
7721 DECL_TI_ARGS appropriately. In particular, they need a
7722 new set of outer arguments, corresponding to the
7723 arguments for this class instantiation.
7725 The same situation can arise with something like this:
7728 template <class T> class C {
7732 when `C<int>' is instantiated. Now, `f(int)' is defined
7735 if (!new_friend_is_defn)
7736 /* On the other hand, if the in-class declaration does
7737 *not* provide a definition, then we don't want to alter
7738 existing definitions. We can just leave everything
7743 tree new_template = TI_TEMPLATE (new_friend_template_info);
7744 tree new_args = TI_ARGS (new_friend_template_info);
7746 /* Overwrite whatever template info was there before, if
7747 any, with the new template information pertaining to
7749 DECL_TEMPLATE_INFO (old_decl) = new_friend_template_info;
7751 if (TREE_CODE (old_decl) != TEMPLATE_DECL)
7753 /* We should have called reregister_specialization in
7755 gcc_assert (retrieve_specialization (new_template,
7759 /* Instantiate it if the global has already been used. */
7760 if (DECL_ODR_USED (old_decl))
7761 instantiate_decl (old_decl, /*defer_ok=*/true,
7762 /*expl_inst_class_mem_p=*/false);
7768 /* Indicate that the old function template is a partial
7770 DECL_TEMPLATE_INFO (DECL_TEMPLATE_RESULT (old_decl))
7771 = new_friend_result_template_info;
7773 gcc_assert (new_template
7774 == most_general_template (new_template));
7775 gcc_assert (new_template != old_decl);
7777 /* Reassign any specializations already in the hash table
7778 to the new more general template, and add the
7779 additional template args. */
7780 for (t = DECL_TEMPLATE_INSTANTIATIONS (old_decl);
7784 tree spec = TREE_VALUE (t);
7787 elt.tmpl = old_decl;
7788 elt.args = DECL_TI_ARGS (spec);
7789 elt.spec = NULL_TREE;
7791 htab_remove_elt (decl_specializations, &elt);
7794 = add_outermost_template_args (new_args,
7795 DECL_TI_ARGS (spec));
7797 register_specialization
7798 (spec, new_template, DECL_TI_ARGS (spec), true, 0);
7801 DECL_TEMPLATE_INSTANTIATIONS (old_decl) = NULL_TREE;
7805 /* The information from NEW_FRIEND has been merged into OLD_DECL
7806 by duplicate_decls. */
7807 new_friend = old_decl;
7812 tree context = DECL_CONTEXT (new_friend);
7816 template <class T> class C {
7817 template <class U> friend void C1<U>::f (); // case 1
7818 friend void C2<T>::f (); // case 2
7820 we only need to make sure CONTEXT is a complete type for
7821 case 2. To distinguish between the two cases, we note that
7822 CONTEXT of case 1 remains dependent type after tsubst while
7823 this isn't true for case 2. */
7824 ++processing_template_decl;
7825 dependent_p = dependent_type_p (context);
7826 --processing_template_decl;
7829 && !complete_type_or_else (context, NULL_TREE))
7830 return error_mark_node;
7832 if (COMPLETE_TYPE_P (context))
7834 /* Check to see that the declaration is really present, and,
7835 possibly obtain an improved declaration. */
7836 tree fn = check_classfn (context,
7837 new_friend, NULL_TREE);
7847 /* FRIEND_TMPL is a friend TEMPLATE_DECL. ARGS is the vector of
7848 template arguments, as for tsubst.
7850 Returns an appropriate tsubst'd friend type or error_mark_node on
7854 tsubst_friend_class (tree friend_tmpl, tree args)
7860 context = CP_DECL_CONTEXT (friend_tmpl);
7862 if (context != global_namespace)
7864 if (TREE_CODE (context) == NAMESPACE_DECL)
7865 push_nested_namespace (context);
7867 push_nested_class (tsubst (context, args, tf_none, NULL_TREE));
7870 /* Look for a class template declaration. We look for hidden names
7871 because two friend declarations of the same template are the
7872 same. For example, in:
7875 template <typename> friend class F;
7877 template <typename> struct B {
7878 template <typename> friend class F;
7881 both F templates are the same. */
7882 tmpl = lookup_name_real (DECL_NAME (friend_tmpl), 0, 0,
7883 /*block_p=*/true, 0,
7884 LOOKUP_COMPLAIN | LOOKUP_HIDDEN);
7886 /* But, if we don't find one, it might be because we're in a
7887 situation like this:
7895 Here, in the scope of (say) S<int>, `S' is bound to a TYPE_DECL
7896 for `S<int>', not the TEMPLATE_DECL. */
7897 if (!tmpl || !DECL_CLASS_TEMPLATE_P (tmpl))
7899 tmpl = lookup_name_prefer_type (DECL_NAME (friend_tmpl), 1);
7900 tmpl = maybe_get_template_decl_from_type_decl (tmpl);
7903 if (tmpl && DECL_CLASS_TEMPLATE_P (tmpl))
7905 /* The friend template has already been declared. Just
7906 check to see that the declarations match, and install any new
7907 default parameters. We must tsubst the default parameters,
7908 of course. We only need the innermost template parameters
7909 because that is all that redeclare_class_template will look
7911 if (TMPL_PARMS_DEPTH (DECL_TEMPLATE_PARMS (friend_tmpl))
7912 > TMPL_ARGS_DEPTH (args))
7915 location_t saved_input_location;
7916 parms = tsubst_template_parms (DECL_TEMPLATE_PARMS (friend_tmpl),
7917 args, tf_warning_or_error);
7919 saved_input_location = input_location;
7920 input_location = DECL_SOURCE_LOCATION (friend_tmpl);
7921 redeclare_class_template (TREE_TYPE (tmpl), parms);
7922 input_location = saved_input_location;
7926 friend_type = TREE_TYPE (tmpl);
7930 /* The friend template has not already been declared. In this
7931 case, the instantiation of the template class will cause the
7932 injection of this template into the global scope. */
7933 tmpl = tsubst (friend_tmpl, args, tf_warning_or_error, NULL_TREE);
7934 if (tmpl == error_mark_node)
7935 return error_mark_node;
7937 /* The new TMPL is not an instantiation of anything, so we
7938 forget its origins. We don't reset CLASSTYPE_TI_TEMPLATE for
7939 the new type because that is supposed to be the corresponding
7940 template decl, i.e., TMPL. */
7941 DECL_USE_TEMPLATE (tmpl) = 0;
7942 DECL_TEMPLATE_INFO (tmpl) = NULL_TREE;
7943 CLASSTYPE_USE_TEMPLATE (TREE_TYPE (tmpl)) = 0;
7944 CLASSTYPE_TI_ARGS (TREE_TYPE (tmpl))
7945 = INNERMOST_TEMPLATE_ARGS (CLASSTYPE_TI_ARGS (TREE_TYPE (tmpl)));
7947 /* Inject this template into the global scope. */
7948 friend_type = TREE_TYPE (pushdecl_top_level_maybe_friend (tmpl, true));
7951 if (context != global_namespace)
7953 if (TREE_CODE (context) == NAMESPACE_DECL)
7954 pop_nested_namespace (context);
7956 pop_nested_class ();
7962 /* Returns zero if TYPE cannot be completed later due to circularity.
7963 Otherwise returns one. */
7966 can_complete_type_without_circularity (tree type)
7968 if (type == NULL_TREE || type == error_mark_node)
7970 else if (COMPLETE_TYPE_P (type))
7972 else if (TREE_CODE (type) == ARRAY_TYPE && TYPE_DOMAIN (type))
7973 return can_complete_type_without_circularity (TREE_TYPE (type));
7974 else if (CLASS_TYPE_P (type)
7975 && TYPE_BEING_DEFINED (TYPE_MAIN_VARIANT (type)))
7981 /* Apply any attributes which had to be deferred until instantiation
7982 time. DECL_P, ATTRIBUTES and ATTR_FLAGS are as cplus_decl_attributes;
7983 ARGS, COMPLAIN, IN_DECL are as tsubst. */
7986 apply_late_template_attributes (tree *decl_p, tree attributes, int attr_flags,
7987 tree args, tsubst_flags_t complain, tree in_decl)
7989 tree last_dep = NULL_TREE;
7993 for (t = attributes; t; t = TREE_CHAIN (t))
7994 if (ATTR_IS_DEPENDENT (t))
7997 attributes = copy_list (attributes);
8001 if (DECL_P (*decl_p))
8003 if (TREE_TYPE (*decl_p) == error_mark_node)
8005 p = &DECL_ATTRIBUTES (*decl_p);
8008 p = &TYPE_ATTRIBUTES (*decl_p);
8012 tree late_attrs = NULL_TREE;
8013 tree *q = &late_attrs;
8015 for (*p = attributes; *p; )
8018 if (ATTR_IS_DEPENDENT (t))
8020 *p = TREE_CHAIN (t);
8021 TREE_CHAIN (t) = NULL_TREE;
8022 /* If the first attribute argument is an identifier, don't
8023 pass it through tsubst. Attributes like mode, format,
8024 cleanup and several target specific attributes expect it
8027 && TREE_CODE (TREE_VALUE (t)) == TREE_LIST
8028 && TREE_VALUE (TREE_VALUE (t))
8029 && (TREE_CODE (TREE_VALUE (TREE_VALUE (t)))
8030 == IDENTIFIER_NODE))
8033 = tsubst_expr (TREE_CHAIN (TREE_VALUE (t)), args, complain,
8035 /*integral_constant_expression_p=*/false);
8036 if (chain != TREE_CHAIN (TREE_VALUE (t)))
8038 = tree_cons (NULL_TREE, TREE_VALUE (TREE_VALUE (t)),
8043 = tsubst_expr (TREE_VALUE (t), args, complain, in_decl,
8044 /*integral_constant_expression_p=*/false);
8046 q = &TREE_CHAIN (t);
8049 p = &TREE_CHAIN (t);
8052 cplus_decl_attributes (decl_p, late_attrs, attr_flags);
8056 /* Perform (or defer) access check for typedefs that were referenced
8057 from within the template TMPL code.
8058 This is a subroutine of instantiate_template and instantiate_class_template.
8059 TMPL is the template to consider and TARGS is the list of arguments of
8063 perform_typedefs_access_check (tree tmpl, tree targs)
8065 location_t saved_location;
8067 qualified_typedef_usage_t *iter;
8070 || (!CLASS_TYPE_P (tmpl)
8071 && TREE_CODE (tmpl) != FUNCTION_DECL))
8074 saved_location = input_location;
8075 FOR_EACH_VEC_ELT (qualified_typedef_usage_t,
8076 get_types_needing_access_check (tmpl),
8079 tree type_decl = iter->typedef_decl;
8080 tree type_scope = iter->context;
8082 if (!type_decl || !type_scope || !CLASS_TYPE_P (type_scope))
8085 if (uses_template_parms (type_decl))
8086 type_decl = tsubst (type_decl, targs, tf_error, NULL_TREE);
8087 if (uses_template_parms (type_scope))
8088 type_scope = tsubst (type_scope, targs, tf_error, NULL_TREE);
8090 /* Make access check error messages point to the location
8091 of the use of the typedef. */
8092 input_location = iter->locus;
8093 perform_or_defer_access_check (TYPE_BINFO (type_scope),
8094 type_decl, type_decl);
8096 input_location = saved_location;
8100 instantiate_class_template (tree type)
8102 tree templ, args, pattern, t, member;
8106 unsigned int saved_maximum_field_alignment;
8108 if (type == error_mark_node)
8109 return error_mark_node;
8111 if (COMPLETE_OR_OPEN_TYPE_P (type)
8112 || uses_template_parms (type))
8115 /* Figure out which template is being instantiated. */
8116 templ = most_general_template (CLASSTYPE_TI_TEMPLATE (type));
8117 gcc_assert (TREE_CODE (templ) == TEMPLATE_DECL);
8119 /* Determine what specialization of the original template to
8121 t = most_specialized_class (type, templ, tf_warning_or_error);
8122 if (t == error_mark_node)
8124 TYPE_BEING_DEFINED (type) = 1;
8125 return error_mark_node;
8129 /* This TYPE is actually an instantiation of a partial
8130 specialization. We replace the innermost set of ARGS with
8131 the arguments appropriate for substitution. For example,
8134 template <class T> struct S {};
8135 template <class T> struct S<T*> {};
8137 and supposing that we are instantiating S<int*>, ARGS will
8138 presently be {int*} -- but we need {int}. */
8139 pattern = TREE_TYPE (t);
8140 args = TREE_PURPOSE (t);
8144 pattern = TREE_TYPE (templ);
8145 args = CLASSTYPE_TI_ARGS (type);
8148 /* If the template we're instantiating is incomplete, then clearly
8149 there's nothing we can do. */
8150 if (!COMPLETE_TYPE_P (pattern))
8153 /* If we've recursively instantiated too many templates, stop. */
8154 if (! push_tinst_level (type))
8157 /* Now we're really doing the instantiation. Mark the type as in
8158 the process of being defined. */
8159 TYPE_BEING_DEFINED (type) = 1;
8161 /* We may be in the middle of deferred access check. Disable
8163 push_deferring_access_checks (dk_no_deferred);
8165 push_to_top_level ();
8166 /* Use #pragma pack from the template context. */
8167 saved_maximum_field_alignment = maximum_field_alignment;
8168 maximum_field_alignment = TYPE_PRECISION (pattern);
8170 SET_CLASSTYPE_INTERFACE_UNKNOWN (type);
8172 /* Set the input location to the most specialized template definition.
8173 This is needed if tsubsting causes an error. */
8174 typedecl = TYPE_MAIN_DECL (pattern);
8175 input_location = DECL_SOURCE_LOCATION (TYPE_NAME (type)) =
8176 DECL_SOURCE_LOCATION (typedecl);
8178 TYPE_HAS_USER_CONSTRUCTOR (type) = TYPE_HAS_USER_CONSTRUCTOR (pattern);
8179 TYPE_HAS_NEW_OPERATOR (type) = TYPE_HAS_NEW_OPERATOR (pattern);
8180 TYPE_HAS_ARRAY_NEW_OPERATOR (type) = TYPE_HAS_ARRAY_NEW_OPERATOR (pattern);
8181 TYPE_GETS_DELETE (type) = TYPE_GETS_DELETE (pattern);
8182 TYPE_HAS_COPY_ASSIGN (type) = TYPE_HAS_COPY_ASSIGN (pattern);
8183 TYPE_HAS_CONST_COPY_ASSIGN (type) = TYPE_HAS_CONST_COPY_ASSIGN (pattern);
8184 TYPE_HAS_COPY_CTOR (type) = TYPE_HAS_COPY_CTOR (pattern);
8185 TYPE_HAS_CONST_COPY_CTOR (type) = TYPE_HAS_CONST_COPY_CTOR (pattern);
8186 TYPE_HAS_DEFAULT_CONSTRUCTOR (type) = TYPE_HAS_DEFAULT_CONSTRUCTOR (pattern);
8187 TYPE_HAS_CONVERSION (type) = TYPE_HAS_CONVERSION (pattern);
8188 TYPE_PACKED (type) = TYPE_PACKED (pattern);
8189 TYPE_ALIGN (type) = TYPE_ALIGN (pattern);
8190 TYPE_USER_ALIGN (type) = TYPE_USER_ALIGN (pattern);
8191 TYPE_FOR_JAVA (type) = TYPE_FOR_JAVA (pattern); /* For libjava's JArray<T> */
8192 if (ANON_AGGR_TYPE_P (pattern))
8193 SET_ANON_AGGR_TYPE_P (type);
8194 if (CLASSTYPE_VISIBILITY_SPECIFIED (pattern))
8196 CLASSTYPE_VISIBILITY_SPECIFIED (type) = 1;
8197 CLASSTYPE_VISIBILITY (type) = CLASSTYPE_VISIBILITY (pattern);
8200 pbinfo = TYPE_BINFO (pattern);
8202 /* We should never instantiate a nested class before its enclosing
8203 class; we need to look up the nested class by name before we can
8204 instantiate it, and that lookup should instantiate the enclosing
8206 gcc_assert (!DECL_CLASS_SCOPE_P (TYPE_MAIN_DECL (pattern))
8207 || COMPLETE_OR_OPEN_TYPE_P (TYPE_CONTEXT (type)));
8209 base_list = NULL_TREE;
8210 if (BINFO_N_BASE_BINFOS (pbinfo))
8216 /* We must enter the scope containing the type, as that is where
8217 the accessibility of types named in dependent bases are
8219 pushed_scope = push_scope (CP_TYPE_CONTEXT (type));
8221 /* Substitute into each of the bases to determine the actual
8223 for (i = 0; BINFO_BASE_ITERATE (pbinfo, i, pbase_binfo); i++)
8226 tree access = BINFO_BASE_ACCESS (pbinfo, i);
8227 tree expanded_bases = NULL_TREE;
8230 if (PACK_EXPANSION_P (BINFO_TYPE (pbase_binfo)))
8233 tsubst_pack_expansion (BINFO_TYPE (pbase_binfo),
8234 args, tf_error, NULL_TREE);
8235 if (expanded_bases == error_mark_node)
8238 len = TREE_VEC_LENGTH (expanded_bases);
8241 for (idx = 0; idx < len; idx++)
8244 /* Extract the already-expanded base class. */
8245 base = TREE_VEC_ELT (expanded_bases, idx);
8247 /* Substitute to figure out the base class. */
8248 base = tsubst (BINFO_TYPE (pbase_binfo), args, tf_error,
8251 if (base == error_mark_node)
8254 base_list = tree_cons (access, base, base_list);
8255 if (BINFO_VIRTUAL_P (pbase_binfo))
8256 TREE_TYPE (base_list) = integer_type_node;
8260 /* The list is now in reverse order; correct that. */
8261 base_list = nreverse (base_list);
8264 pop_scope (pushed_scope);
8266 /* Now call xref_basetypes to set up all the base-class
8268 xref_basetypes (type, base_list);
8270 apply_late_template_attributes (&type, TYPE_ATTRIBUTES (pattern),
8271 (int) ATTR_FLAG_TYPE_IN_PLACE,
8272 args, tf_error, NULL_TREE);
8273 fixup_attribute_variants (type);
8275 /* Now that our base classes are set up, enter the scope of the
8276 class, so that name lookups into base classes, etc. will work
8277 correctly. This is precisely analogous to what we do in
8278 begin_class_definition when defining an ordinary non-template
8279 class, except we also need to push the enclosing classes. */
8280 push_nested_class (type);
8282 /* Now members are processed in the order of declaration. */
8283 for (member = CLASSTYPE_DECL_LIST (pattern);
8284 member; member = TREE_CHAIN (member))
8286 tree t = TREE_VALUE (member);
8288 if (TREE_PURPOSE (member))
8292 /* Build new CLASSTYPE_NESTED_UTDS. */
8295 bool class_template_p;
8297 class_template_p = (TREE_CODE (t) != ENUMERAL_TYPE
8298 && TYPE_LANG_SPECIFIC (t)
8299 && CLASSTYPE_IS_TEMPLATE (t));
8300 /* If the member is a class template, then -- even after
8301 substitution -- there may be dependent types in the
8302 template argument list for the class. We increment
8303 PROCESSING_TEMPLATE_DECL so that dependent_type_p, as
8304 that function will assume that no types are dependent
8305 when outside of a template. */
8306 if (class_template_p)
8307 ++processing_template_decl;
8308 newtag = tsubst (t, args, tf_error, NULL_TREE);
8309 if (class_template_p)
8310 --processing_template_decl;
8311 if (newtag == error_mark_node)
8314 if (TREE_CODE (newtag) != ENUMERAL_TYPE)
8316 tree name = TYPE_IDENTIFIER (t);
8318 if (class_template_p)
8319 /* Unfortunately, lookup_template_class sets
8320 CLASSTYPE_IMPLICIT_INSTANTIATION for a partial
8321 instantiation (i.e., for the type of a member
8322 template class nested within a template class.)
8323 This behavior is required for
8324 maybe_process_partial_specialization to work
8325 correctly, but is not accurate in this case;
8326 the TAG is not an instantiation of anything.
8327 (The corresponding TEMPLATE_DECL is an
8328 instantiation, but the TYPE is not.) */
8329 CLASSTYPE_USE_TEMPLATE (newtag) = 0;
8331 /* Now, we call pushtag to put this NEWTAG into the scope of
8332 TYPE. We first set up the IDENTIFIER_TYPE_VALUE to avoid
8333 pushtag calling push_template_decl. We don't have to do
8334 this for enums because it will already have been done in
8337 SET_IDENTIFIER_TYPE_VALUE (name, newtag);
8338 pushtag (name, newtag, /*tag_scope=*/ts_current);
8341 else if (TREE_CODE (t) == FUNCTION_DECL
8342 || DECL_FUNCTION_TEMPLATE_P (t))
8344 /* Build new TYPE_METHODS. */
8347 if (TREE_CODE (t) == TEMPLATE_DECL)
8348 ++processing_template_decl;
8349 r = tsubst (t, args, tf_error, NULL_TREE);
8350 if (TREE_CODE (t) == TEMPLATE_DECL)
8351 --processing_template_decl;
8352 set_current_access_from_decl (r);
8353 finish_member_declaration (r);
8357 /* Build new TYPE_FIELDS. */
8358 if (TREE_CODE (t) == STATIC_ASSERT)
8361 tsubst_expr (STATIC_ASSERT_CONDITION (t), args,
8362 tf_warning_or_error, NULL_TREE,
8363 /*integral_constant_expression_p=*/true);
8364 finish_static_assert (condition,
8365 STATIC_ASSERT_MESSAGE (t),
8366 STATIC_ASSERT_SOURCE_LOCATION (t),
8369 else if (TREE_CODE (t) != CONST_DECL)
8373 /* The file and line for this declaration, to
8374 assist in error message reporting. Since we
8375 called push_tinst_level above, we don't need to
8377 input_location = DECL_SOURCE_LOCATION (t);
8379 if (TREE_CODE (t) == TEMPLATE_DECL)
8380 ++processing_template_decl;
8381 r = tsubst (t, args, tf_warning_or_error, NULL_TREE);
8382 if (TREE_CODE (t) == TEMPLATE_DECL)
8383 --processing_template_decl;
8384 if (TREE_CODE (r) == VAR_DECL)
8388 [t]he initialization (and any associated
8389 side-effects) of a static data member does
8390 not occur unless the static data member is
8391 itself used in a way that requires the
8392 definition of the static data member to
8395 Therefore, we do not substitute into the
8396 initialized for the static data member here. */
8397 finish_static_data_member_decl
8400 /*init_const_expr_p=*/false,
8401 /*asmspec_tree=*/NULL_TREE,
8403 if (DECL_INITIALIZED_IN_CLASS_P (r))
8404 check_static_variable_definition (r, TREE_TYPE (r));
8406 else if (TREE_CODE (r) == FIELD_DECL)
8408 /* Determine whether R has a valid type and can be
8409 completed later. If R is invalid, then it is
8410 replaced by error_mark_node so that it will not be
8411 added to TYPE_FIELDS. */
8412 tree rtype = TREE_TYPE (r);
8413 if (can_complete_type_without_circularity (rtype))
8414 complete_type (rtype);
8416 if (!COMPLETE_TYPE_P (rtype))
8418 cxx_incomplete_type_error (r, rtype);
8419 r = error_mark_node;
8423 /* If it is a TYPE_DECL for a class-scoped ENUMERAL_TYPE,
8424 such a thing will already have been added to the field
8425 list by tsubst_enum in finish_member_declaration in the
8426 CLASSTYPE_NESTED_UTDS case above. */
8427 if (!(TREE_CODE (r) == TYPE_DECL
8428 && TREE_CODE (TREE_TYPE (r)) == ENUMERAL_TYPE
8429 && DECL_ARTIFICIAL (r)))
8431 set_current_access_from_decl (r);
8432 finish_member_declaration (r);
8439 if (TYPE_P (t) || DECL_CLASS_TEMPLATE_P (t))
8441 /* Build new CLASSTYPE_FRIEND_CLASSES. */
8443 tree friend_type = t;
8444 bool adjust_processing_template_decl = false;
8446 if (TREE_CODE (friend_type) == TEMPLATE_DECL)
8448 /* template <class T> friend class C; */
8449 friend_type = tsubst_friend_class (friend_type, args);
8450 adjust_processing_template_decl = true;
8452 else if (TREE_CODE (friend_type) == UNBOUND_CLASS_TEMPLATE)
8454 /* template <class T> friend class C::D; */
8455 friend_type = tsubst (friend_type, args,
8456 tf_warning_or_error, NULL_TREE);
8457 if (TREE_CODE (friend_type) == TEMPLATE_DECL)
8458 friend_type = TREE_TYPE (friend_type);
8459 adjust_processing_template_decl = true;
8461 else if (TREE_CODE (friend_type) == TYPENAME_TYPE)
8463 /* This could be either
8467 when dependent_type_p is false or
8469 template <class U> friend class T::C;
8472 friend_type = tsubst (friend_type, args,
8473 tf_warning_or_error, NULL_TREE);
8474 /* Bump processing_template_decl for correct
8475 dependent_type_p calculation. */
8476 ++processing_template_decl;
8477 if (dependent_type_p (friend_type))
8478 adjust_processing_template_decl = true;
8479 --processing_template_decl;
8481 else if (!CLASSTYPE_USE_TEMPLATE (friend_type)
8482 && hidden_name_p (TYPE_NAME (friend_type)))
8486 where C hasn't been declared yet. Let's lookup name
8487 from namespace scope directly, bypassing any name that
8488 come from dependent base class. */
8489 tree ns = decl_namespace_context (TYPE_MAIN_DECL (friend_type));
8491 /* The call to xref_tag_from_type does injection for friend
8493 push_nested_namespace (ns);
8495 xref_tag_from_type (friend_type, NULL_TREE,
8496 /*tag_scope=*/ts_current);
8497 pop_nested_namespace (ns);
8499 else if (uses_template_parms (friend_type))
8500 /* friend class C<T>; */
8501 friend_type = tsubst (friend_type, args,
8502 tf_warning_or_error, NULL_TREE);
8507 where C is already declared or
8509 friend class C<int>;
8511 We don't have to do anything in these cases. */
8513 if (adjust_processing_template_decl)
8514 /* Trick make_friend_class into realizing that the friend
8515 we're adding is a template, not an ordinary class. It's
8516 important that we use make_friend_class since it will
8517 perform some error-checking and output cross-reference
8519 ++processing_template_decl;
8521 if (friend_type != error_mark_node)
8522 make_friend_class (type, friend_type, /*complain=*/false);
8524 if (adjust_processing_template_decl)
8525 --processing_template_decl;
8529 /* Build new DECL_FRIENDLIST. */
8532 /* The file and line for this declaration, to
8533 assist in error message reporting. Since we
8534 called push_tinst_level above, we don't need to
8536 input_location = DECL_SOURCE_LOCATION (t);
8538 if (TREE_CODE (t) == TEMPLATE_DECL)
8540 ++processing_template_decl;
8541 push_deferring_access_checks (dk_no_check);
8544 r = tsubst_friend_function (t, args);
8545 add_friend (type, r, /*complain=*/false);
8546 if (TREE_CODE (t) == TEMPLATE_DECL)
8548 pop_deferring_access_checks ();
8549 --processing_template_decl;
8555 /* Set the file and line number information to whatever is given for
8556 the class itself. This puts error messages involving generated
8557 implicit functions at a predictable point, and the same point
8558 that would be used for non-template classes. */
8559 input_location = DECL_SOURCE_LOCATION (typedecl);
8561 unreverse_member_declarations (type);
8562 finish_struct_1 (type);
8563 TYPE_BEING_DEFINED (type) = 0;
8565 /* We don't instantiate default arguments for member functions. 14.7.1:
8567 The implicit instantiation of a class template specialization causes
8568 the implicit instantiation of the declarations, but not of the
8569 definitions or default arguments, of the class member functions,
8570 member classes, static data members and member templates.... */
8572 /* Some typedefs referenced from within the template code need to be access
8573 checked at template instantiation time, i.e now. These types were
8574 added to the template at parsing time. Let's get those and perform
8575 the access checks then. */
8576 perform_typedefs_access_check (pattern, args);
8577 perform_deferred_access_checks ();
8578 pop_nested_class ();
8579 maximum_field_alignment = saved_maximum_field_alignment;
8580 pop_from_top_level ();
8581 pop_deferring_access_checks ();
8584 /* The vtable for a template class can be emitted in any translation
8585 unit in which the class is instantiated. When there is no key
8586 method, however, finish_struct_1 will already have added TYPE to
8587 the keyed_classes list. */
8588 if (TYPE_CONTAINS_VPTR_P (type) && CLASSTYPE_KEY_METHOD (type))
8589 keyed_classes = tree_cons (NULL_TREE, type, keyed_classes);
8595 tsubst_template_arg (tree t, tree args, tsubst_flags_t complain, tree in_decl)
8601 else if (TYPE_P (t))
8602 r = tsubst (t, args, complain, in_decl);
8605 if (!(complain & tf_warning))
8606 ++c_inhibit_evaluation_warnings;
8607 r = tsubst_expr (t, args, complain, in_decl,
8608 /*integral_constant_expression_p=*/true);
8609 if (!(complain & tf_warning))
8610 --c_inhibit_evaluation_warnings;
8615 /* Give a chain SPEC_PARM of PARM_DECLs, pack them into a
8616 NONTYPE_ARGUMENT_PACK. */
8619 make_fnparm_pack (tree spec_parm)
8621 /* Collect all of the extra "packed" parameters into an
8625 tree argpack = make_node (NONTYPE_ARGUMENT_PACK);
8626 tree argtypepack = cxx_make_type (TYPE_ARGUMENT_PACK);
8627 int i, len = list_length (spec_parm);
8629 /* Fill in PARMVEC and PARMTYPEVEC with all of the parameters. */
8630 parmvec = make_tree_vec (len);
8631 parmtypevec = make_tree_vec (len);
8632 for (i = 0; i < len; i++, spec_parm = DECL_CHAIN (spec_parm))
8634 TREE_VEC_ELT (parmvec, i) = spec_parm;
8635 TREE_VEC_ELT (parmtypevec, i) = TREE_TYPE (spec_parm);
8638 /* Build the argument packs. */
8639 SET_ARGUMENT_PACK_ARGS (argpack, parmvec);
8640 SET_ARGUMENT_PACK_ARGS (argtypepack, parmtypevec);
8641 TREE_TYPE (argpack) = argtypepack;
8646 /* Substitute ARGS into T, which is an pack expansion
8647 (i.e. TYPE_PACK_EXPANSION or EXPR_PACK_EXPANSION). Returns a
8648 TREE_VEC with the substituted arguments, a PACK_EXPANSION_* node
8649 (if only a partial substitution could be performed) or
8650 ERROR_MARK_NODE if there was an error. */
8652 tsubst_pack_expansion (tree t, tree args, tsubst_flags_t complain,
8656 tree pack, packs = NULL_TREE, unsubstituted_packs = NULL_TREE;
8660 htab_t saved_local_specializations = NULL;
8662 gcc_assert (PACK_EXPANSION_P (t));
8663 pattern = PACK_EXPANSION_PATTERN (t);
8665 /* Determine the argument packs that will instantiate the parameter
8666 packs used in the expansion expression. While we're at it,
8667 compute the number of arguments to be expanded and make sure it
8669 for (pack = PACK_EXPANSION_PARAMETER_PACKS (t); pack;
8670 pack = TREE_CHAIN (pack))
8672 tree parm_pack = TREE_VALUE (pack);
8673 tree arg_pack = NULL_TREE;
8674 tree orig_arg = NULL_TREE;
8676 if (TREE_CODE (parm_pack) == PARM_DECL)
8678 if (!cp_unevaluated_operand)
8679 arg_pack = retrieve_local_specialization (parm_pack);
8682 /* We can't rely on local_specializations for a parameter
8683 name used later in a function declaration (such as in a
8684 late-specified return type). Even if it exists, it might
8685 have the wrong value for a recursive call. Just make a
8686 dummy decl, since it's only used for its type. */
8687 arg_pack = tsubst_decl (parm_pack, args, complain);
8688 arg_pack = make_fnparm_pack (arg_pack);
8693 int level, idx, levels;
8694 template_parm_level_and_index (parm_pack, &level, &idx);
8696 levels = TMPL_ARGS_DEPTH (args);
8697 if (level <= levels)
8698 arg_pack = TMPL_ARG (args, level, idx);
8701 orig_arg = arg_pack;
8702 if (arg_pack && TREE_CODE (arg_pack) == ARGUMENT_PACK_SELECT)
8703 arg_pack = ARGUMENT_PACK_SELECT_FROM_PACK (arg_pack);
8705 if (arg_pack && !ARGUMENT_PACK_P (arg_pack))
8706 /* This can only happen if we forget to expand an argument
8707 pack somewhere else. Just return an error, silently. */
8709 result = make_tree_vec (1);
8710 TREE_VEC_ELT (result, 0) = error_mark_node;
8715 && TREE_VEC_LENGTH (ARGUMENT_PACK_ARGS (arg_pack)) == 1
8716 && PACK_EXPANSION_P (TREE_VEC_ELT (ARGUMENT_PACK_ARGS (arg_pack), 0)))
8718 tree expansion = TREE_VEC_ELT (ARGUMENT_PACK_ARGS (arg_pack), 0);
8719 tree pattern = PACK_EXPANSION_PATTERN (expansion);
8720 if ((TYPE_P (pattern) && same_type_p (pattern, parm_pack))
8721 || (!TYPE_P (pattern) && cp_tree_equal (parm_pack, pattern)))
8722 /* The argument pack that the parameter maps to is just an
8723 expansion of the parameter itself, such as one would
8724 find in the implicit typedef of a class inside the
8725 class itself. Consider this parameter "unsubstituted",
8726 so that we will maintain the outer pack expansion. */
8727 arg_pack = NULL_TREE;
8733 TREE_VEC_LENGTH (ARGUMENT_PACK_ARGS (arg_pack));
8735 /* It's all-or-nothing with incomplete argument packs. */
8736 if (incomplete && !ARGUMENT_PACK_INCOMPLETE_P (arg_pack))
8737 return error_mark_node;
8739 if (ARGUMENT_PACK_INCOMPLETE_P (arg_pack))
8744 else if (len != my_len)
8747 /* We got explicit args for some packs but not others;
8748 do nothing now and try again after deduction. */
8750 if (TREE_CODE (t) == TYPE_PACK_EXPANSION)
8751 error ("mismatched argument pack lengths while expanding "
8755 error ("mismatched argument pack lengths while expanding "
8758 return error_mark_node;
8761 /* Keep track of the parameter packs and their corresponding
8763 packs = tree_cons (parm_pack, arg_pack, packs);
8764 TREE_TYPE (packs) = orig_arg;
8767 /* We can't substitute for this parameter pack. */
8768 unsubstituted_packs = tree_cons (TREE_PURPOSE (pack),
8770 unsubstituted_packs);
8773 /* We cannot expand this expansion expression, because we don't have
8774 all of the argument packs we need. Substitute into the pattern
8775 and return a PACK_EXPANSION_*. The caller will need to deal with
8777 if (unsubstituted_packs)
8780 if (TREE_CODE (t) == EXPR_PACK_EXPANSION)
8781 new_pat = tsubst_expr (pattern, args, complain, in_decl,
8782 /*integral_constant_expression_p=*/false);
8784 new_pat = tsubst (pattern, args, complain, in_decl);
8785 return make_pack_expansion (new_pat);
8788 /* We could not find any argument packs that work. */
8790 return error_mark_node;
8792 if (cp_unevaluated_operand)
8794 /* We're in a late-specified return type, so create our own local
8795 specializations table; the current table is either NULL or (in the
8796 case of recursive unification) might have bindings that we don't
8797 want to use or alter. */
8798 saved_local_specializations = local_specializations;
8799 local_specializations = htab_create (37,
8800 hash_local_specialization,
8801 eq_local_specializations,
8805 /* For each argument in each argument pack, substitute into the
8807 result = make_tree_vec (len + incomplete);
8808 for (i = 0; i < len + incomplete; ++i)
8810 /* For parameter pack, change the substitution of the parameter
8811 pack to the ith argument in its argument pack, then expand
8813 for (pack = packs; pack; pack = TREE_CHAIN (pack))
8815 tree parm = TREE_PURPOSE (pack);
8817 if (TREE_CODE (parm) == PARM_DECL)
8819 /* Select the Ith argument from the pack. */
8820 tree arg = make_node (ARGUMENT_PACK_SELECT);
8821 ARGUMENT_PACK_SELECT_FROM_PACK (arg) = TREE_VALUE (pack);
8822 ARGUMENT_PACK_SELECT_INDEX (arg) = i;
8824 register_local_specialization (arg, parm);
8830 template_parm_level_and_index (parm, &level, &idx);
8834 /* Select the Ith argument from the pack. */
8835 value = make_node (ARGUMENT_PACK_SELECT);
8836 ARGUMENT_PACK_SELECT_FROM_PACK (value) = TREE_VALUE (pack);
8837 ARGUMENT_PACK_SELECT_INDEX (value) = i;
8840 /* Update the corresponding argument. */
8841 TMPL_ARG (args, level, idx) = value;
8845 /* Substitute into the PATTERN with the altered arguments. */
8846 if (TREE_CODE (t) == EXPR_PACK_EXPANSION)
8847 TREE_VEC_ELT (result, i) =
8848 tsubst_expr (pattern, args, complain, in_decl,
8849 /*integral_constant_expression_p=*/false);
8851 TREE_VEC_ELT (result, i) = tsubst (pattern, args, complain, in_decl);
8854 /* When we have incomplete argument packs, the last "expanded"
8855 result is itself a pack expansion, which allows us
8856 to deduce more arguments. */
8857 TREE_VEC_ELT (result, i) =
8858 make_pack_expansion (TREE_VEC_ELT (result, i));
8860 if (TREE_VEC_ELT (result, i) == error_mark_node)
8862 result = error_mark_node;
8867 /* Update ARGS to restore the substitution from parameter packs to
8868 their argument packs. */
8869 for (pack = packs; pack; pack = TREE_CHAIN (pack))
8871 tree parm = TREE_PURPOSE (pack);
8873 if (TREE_CODE (parm) == PARM_DECL)
8874 register_local_specialization (TREE_TYPE (pack), parm);
8878 template_parm_level_and_index (parm, &level, &idx);
8880 /* Update the corresponding argument. */
8881 if (TMPL_ARGS_HAVE_MULTIPLE_LEVELS (args))
8882 TREE_VEC_ELT (TREE_VEC_ELT (args, level -1 ), idx) =
8885 TREE_VEC_ELT (args, idx) = TREE_TYPE (pack);
8889 if (saved_local_specializations)
8891 htab_delete (local_specializations);
8892 local_specializations = saved_local_specializations;
8898 /* Given PARM_DECL PARM, find the corresponding PARM_DECL in the template
8899 TMPL. We do this using DECL_PARM_INDEX, which should work even with
8900 parameter packs; all parms generated from a function parameter pack will
8901 have the same DECL_PARM_INDEX. */
8904 get_pattern_parm (tree parm, tree tmpl)
8906 tree pattern = DECL_TEMPLATE_RESULT (tmpl);
8909 if (DECL_ARTIFICIAL (parm))
8911 for (patparm = DECL_ARGUMENTS (pattern);
8912 patparm; patparm = DECL_CHAIN (patparm))
8913 if (DECL_ARTIFICIAL (patparm)
8914 && DECL_NAME (parm) == DECL_NAME (patparm))
8919 patparm = FUNCTION_FIRST_USER_PARM (DECL_TEMPLATE_RESULT (tmpl));
8920 patparm = chain_index (DECL_PARM_INDEX (parm)-1, patparm);
8921 gcc_assert (DECL_PARM_INDEX (patparm)
8922 == DECL_PARM_INDEX (parm));
8928 /* Substitute ARGS into the vector or list of template arguments T. */
8931 tsubst_template_args (tree t, tree args, tsubst_flags_t complain, tree in_decl)
8934 int len = TREE_VEC_LENGTH (t);
8935 int need_new = 0, i, expanded_len_adjust = 0, out;
8936 tree *elts = XALLOCAVEC (tree, len);
8938 for (i = 0; i < len; i++)
8940 tree orig_arg = TREE_VEC_ELT (t, i);
8943 if (TREE_CODE (orig_arg) == TREE_VEC)
8944 new_arg = tsubst_template_args (orig_arg, args, complain, in_decl);
8945 else if (PACK_EXPANSION_P (orig_arg))
8947 /* Substitute into an expansion expression. */
8948 new_arg = tsubst_pack_expansion (orig_arg, args, complain, in_decl);
8950 if (TREE_CODE (new_arg) == TREE_VEC)
8951 /* Add to the expanded length adjustment the number of
8952 expanded arguments. We subtract one from this
8953 measurement, because the argument pack expression
8954 itself is already counted as 1 in
8955 LEN. EXPANDED_LEN_ADJUST can actually be negative, if
8956 the argument pack is empty. */
8957 expanded_len_adjust += TREE_VEC_LENGTH (new_arg) - 1;
8959 else if (ARGUMENT_PACK_P (orig_arg))
8961 /* Substitute into each of the arguments. */
8962 new_arg = TYPE_P (orig_arg)
8963 ? cxx_make_type (TREE_CODE (orig_arg))
8964 : make_node (TREE_CODE (orig_arg));
8966 SET_ARGUMENT_PACK_ARGS (
8968 tsubst_template_args (ARGUMENT_PACK_ARGS (orig_arg),
8969 args, complain, in_decl));
8971 if (ARGUMENT_PACK_ARGS (new_arg) == error_mark_node)
8972 new_arg = error_mark_node;
8974 if (TREE_CODE (new_arg) == NONTYPE_ARGUMENT_PACK) {
8975 TREE_TYPE (new_arg) = tsubst (TREE_TYPE (orig_arg), args,
8977 TREE_CONSTANT (new_arg) = TREE_CONSTANT (orig_arg);
8979 if (TREE_TYPE (new_arg) == error_mark_node)
8980 new_arg = error_mark_node;
8984 new_arg = tsubst_template_arg (orig_arg, args, complain, in_decl);
8986 if (new_arg == error_mark_node)
8987 return error_mark_node;
8990 if (new_arg != orig_arg)
8997 /* Make space for the expanded arguments coming from template
8999 t = make_tree_vec (len + expanded_len_adjust);
9000 /* ORIG_T can contain TREE_VECs. That happens if ORIG_T contains the
9001 arguments for a member template.
9002 In that case each TREE_VEC in ORIG_T represents a level of template
9003 arguments, and ORIG_T won't carry any non defaulted argument count.
9004 It will rather be the nested TREE_VECs that will carry one.
9005 In other words, ORIG_T carries a non defaulted argument count only
9006 if it doesn't contain any nested TREE_VEC. */
9007 if (NON_DEFAULT_TEMPLATE_ARGS_COUNT (orig_t))
9009 int count = GET_NON_DEFAULT_TEMPLATE_ARGS_COUNT (orig_t);
9010 count += expanded_len_adjust;
9011 SET_NON_DEFAULT_TEMPLATE_ARGS_COUNT (t, count);
9013 for (i = 0, out = 0; i < len; i++)
9015 if ((PACK_EXPANSION_P (TREE_VEC_ELT (orig_t, i))
9016 || ARGUMENT_PACK_P (TREE_VEC_ELT (orig_t, i)))
9017 && TREE_CODE (elts[i]) == TREE_VEC)
9021 /* Now expand the template argument pack "in place". */
9022 for (idx = 0; idx < TREE_VEC_LENGTH (elts[i]); idx++, out++)
9023 TREE_VEC_ELT (t, out) = TREE_VEC_ELT (elts[i], idx);
9027 TREE_VEC_ELT (t, out) = elts[i];
9035 /* Return the result of substituting ARGS into the template parameters
9036 given by PARMS. If there are m levels of ARGS and m + n levels of
9037 PARMS, then the result will contain n levels of PARMS. For
9038 example, if PARMS is `template <class T> template <class U>
9039 template <T*, U, class V>' and ARGS is {{int}, {double}} then the
9040 result will be `template <int*, double, class V>'. */
9043 tsubst_template_parms (tree parms, tree args, tsubst_flags_t complain)
9048 /* When substituting into a template, we must set
9049 PROCESSING_TEMPLATE_DECL as the template parameters may be
9050 dependent if they are based on one-another, and the dependency
9051 predicates are short-circuit outside of templates. */
9052 ++processing_template_decl;
9054 for (new_parms = &r;
9055 TMPL_PARMS_DEPTH (parms) > TMPL_ARGS_DEPTH (args);
9056 new_parms = &(TREE_CHAIN (*new_parms)),
9057 parms = TREE_CHAIN (parms))
9060 make_tree_vec (TREE_VEC_LENGTH (TREE_VALUE (parms)));
9063 for (i = 0; i < TREE_VEC_LENGTH (new_vec); ++i)
9067 if (parms == error_mark_node)
9070 tuple = TREE_VEC_ELT (TREE_VALUE (parms), i);
9072 if (tuple == error_mark_node)
9075 TREE_VEC_ELT (new_vec, i) =
9076 tsubst_template_parm (tuple, args, complain);
9080 tree_cons (size_int (TMPL_PARMS_DEPTH (parms)
9081 - TMPL_ARGS_DEPTH (args)),
9082 new_vec, NULL_TREE);
9085 --processing_template_decl;
9090 /* Return the result of substituting ARGS into one template parameter
9091 given by T. T Must be a TREE_LIST which TREE_VALUE is the template
9092 parameter and which TREE_PURPOSE is the default argument of the
9093 template parameter. */
9096 tsubst_template_parm (tree t, tree args, tsubst_flags_t complain)
9098 tree default_value, parm_decl;
9100 if (args == NULL_TREE
9102 || t == error_mark_node)
9105 gcc_assert (TREE_CODE (t) == TREE_LIST);
9107 default_value = TREE_PURPOSE (t);
9108 parm_decl = TREE_VALUE (t);
9110 parm_decl = tsubst (parm_decl, args, complain, NULL_TREE);
9111 if (TREE_CODE (parm_decl) == PARM_DECL
9112 && invalid_nontype_parm_type_p (TREE_TYPE (parm_decl), complain))
9113 parm_decl = error_mark_node;
9114 default_value = tsubst_template_arg (default_value, args,
9115 complain, NULL_TREE);
9117 return build_tree_list (default_value, parm_decl);
9120 /* Substitute the ARGS into the indicated aggregate (or enumeration)
9121 type T. If T is not an aggregate or enumeration type, it is
9122 handled as if by tsubst. IN_DECL is as for tsubst. If
9123 ENTERING_SCOPE is nonzero, T is the context for a template which
9124 we are presently tsubst'ing. Return the substituted value. */
9127 tsubst_aggr_type (tree t,
9129 tsubst_flags_t complain,
9136 switch (TREE_CODE (t))
9139 if (TYPE_PTRMEMFUNC_P (t))
9140 return tsubst (TYPE_PTRMEMFUNC_FN_TYPE (t), args, complain, in_decl);
9142 /* Else fall through. */
9145 if (TYPE_TEMPLATE_INFO (t) && uses_template_parms (t))
9150 int saved_unevaluated_operand;
9151 int saved_inhibit_evaluation_warnings;
9153 /* In "sizeof(X<I>)" we need to evaluate "I". */
9154 saved_unevaluated_operand = cp_unevaluated_operand;
9155 cp_unevaluated_operand = 0;
9156 saved_inhibit_evaluation_warnings = c_inhibit_evaluation_warnings;
9157 c_inhibit_evaluation_warnings = 0;
9159 /* First, determine the context for the type we are looking
9161 context = TYPE_CONTEXT (t);
9164 context = tsubst_aggr_type (context, args, complain,
9165 in_decl, /*entering_scope=*/1);
9166 /* If context is a nested class inside a class template,
9167 it may still need to be instantiated (c++/33959). */
9168 if (TYPE_P (context))
9169 context = complete_type (context);
9172 /* Then, figure out what arguments are appropriate for the
9173 type we are trying to find. For example, given:
9175 template <class T> struct S;
9176 template <class T, class U> void f(T, U) { S<U> su; }
9178 and supposing that we are instantiating f<int, double>,
9179 then our ARGS will be {int, double}, but, when looking up
9180 S we only want {double}. */
9181 argvec = tsubst_template_args (TYPE_TI_ARGS (t), args,
9183 if (argvec == error_mark_node)
9184 r = error_mark_node;
9187 r = lookup_template_class (t, argvec, in_decl, context,
9188 entering_scope, complain);
9189 r = cp_build_qualified_type_real (r, cp_type_quals (t), complain);
9192 cp_unevaluated_operand = saved_unevaluated_operand;
9193 c_inhibit_evaluation_warnings = saved_inhibit_evaluation_warnings;
9198 /* This is not a template type, so there's nothing to do. */
9202 return tsubst (t, args, complain, in_decl);
9206 /* Substitute into the default argument ARG (a default argument for
9207 FN), which has the indicated TYPE. */
9210 tsubst_default_argument (tree fn, tree type, tree arg)
9212 tree saved_class_ptr = NULL_TREE;
9213 tree saved_class_ref = NULL_TREE;
9215 /* This can happen in invalid code. */
9216 if (TREE_CODE (arg) == DEFAULT_ARG)
9219 /* This default argument came from a template. Instantiate the
9220 default argument here, not in tsubst. In the case of
9229 we must be careful to do name lookup in the scope of S<T>,
9230 rather than in the current class. */
9231 push_access_scope (fn);
9232 /* The "this" pointer is not valid in a default argument. */
9235 saved_class_ptr = current_class_ptr;
9236 cp_function_chain->x_current_class_ptr = NULL_TREE;
9237 saved_class_ref = current_class_ref;
9238 cp_function_chain->x_current_class_ref = NULL_TREE;
9241 push_deferring_access_checks(dk_no_deferred);
9242 /* The default argument expression may cause implicitly defined
9243 member functions to be synthesized, which will result in garbage
9244 collection. We must treat this situation as if we were within
9245 the body of function so as to avoid collecting live data on the
9248 arg = tsubst_expr (arg, DECL_TI_ARGS (fn),
9249 tf_warning_or_error, NULL_TREE,
9250 /*integral_constant_expression_p=*/false);
9252 pop_deferring_access_checks();
9254 /* Restore the "this" pointer. */
9257 cp_function_chain->x_current_class_ptr = saved_class_ptr;
9258 cp_function_chain->x_current_class_ref = saved_class_ref;
9261 /* Make sure the default argument is reasonable. */
9262 arg = check_default_argument (type, arg);
9264 pop_access_scope (fn);
9269 /* Substitute into all the default arguments for FN. */
9272 tsubst_default_arguments (tree fn)
9277 tmpl_args = DECL_TI_ARGS (fn);
9279 /* If this function is not yet instantiated, we certainly don't need
9280 its default arguments. */
9281 if (uses_template_parms (tmpl_args))
9283 /* Don't do this again for clones. */
9284 if (DECL_CLONED_FUNCTION_P (fn))
9287 for (arg = TYPE_ARG_TYPES (TREE_TYPE (fn));
9289 arg = TREE_CHAIN (arg))
9290 if (TREE_PURPOSE (arg))
9291 TREE_PURPOSE (arg) = tsubst_default_argument (fn,
9293 TREE_PURPOSE (arg));
9296 /* Substitute the ARGS into the T, which is a _DECL. Return the
9297 result of the substitution. Issue error and warning messages under
9298 control of COMPLAIN. */
9301 tsubst_decl (tree t, tree args, tsubst_flags_t complain)
9303 #define RETURN(EXP) do { r = (EXP); goto out; } while(0)
9304 location_t saved_loc;
9309 /* Set the filename and linenumber to improve error-reporting. */
9310 saved_loc = input_location;
9311 input_location = DECL_SOURCE_LOCATION (t);
9313 switch (TREE_CODE (t))
9317 /* We can get here when processing a member function template,
9318 member class template, or template template parameter. */
9319 tree decl = DECL_TEMPLATE_RESULT (t);
9324 if (DECL_TEMPLATE_TEMPLATE_PARM_P (t))
9326 /* Template template parameter is treated here. */
9327 tree new_type = tsubst (TREE_TYPE (t), args, complain, in_decl);
9328 if (new_type == error_mark_node)
9329 RETURN (error_mark_node);
9332 DECL_CHAIN (r) = NULL_TREE;
9333 TREE_TYPE (r) = new_type;
9334 DECL_TEMPLATE_RESULT (r)
9335 = build_decl (DECL_SOURCE_LOCATION (decl),
9336 TYPE_DECL, DECL_NAME (decl), new_type);
9337 DECL_TEMPLATE_PARMS (r)
9338 = tsubst_template_parms (DECL_TEMPLATE_PARMS (t), args,
9340 TYPE_NAME (new_type) = r;
9344 /* We might already have an instance of this template.
9345 The ARGS are for the surrounding class type, so the
9346 full args contain the tsubst'd args for the context,
9347 plus the innermost args from the template decl. */
9348 tmpl_args = DECL_CLASS_TEMPLATE_P (t)
9349 ? CLASSTYPE_TI_ARGS (TREE_TYPE (t))
9350 : DECL_TI_ARGS (DECL_TEMPLATE_RESULT (t));
9351 /* Because this is a template, the arguments will still be
9352 dependent, even after substitution. If
9353 PROCESSING_TEMPLATE_DECL is not set, the dependency
9354 predicates will short-circuit. */
9355 ++processing_template_decl;
9356 full_args = tsubst_template_args (tmpl_args, args,
9358 --processing_template_decl;
9359 if (full_args == error_mark_node)
9360 RETURN (error_mark_node);
9362 /* If this is a default template template argument,
9363 tsubst might not have changed anything. */
9364 if (full_args == tmpl_args)
9367 hash = hash_tmpl_and_args (t, full_args);
9368 spec = retrieve_specialization (t, full_args, hash);
9369 if (spec != NULL_TREE)
9375 /* Make a new template decl. It will be similar to the
9376 original, but will record the current template arguments.
9377 We also create a new function declaration, which is just
9378 like the old one, but points to this new template, rather
9379 than the old one. */
9381 gcc_assert (DECL_LANG_SPECIFIC (r) != 0);
9382 DECL_CHAIN (r) = NULL_TREE;
9384 DECL_TEMPLATE_INFO (r) = build_template_info (t, args);
9386 if (TREE_CODE (decl) == TYPE_DECL)
9389 ++processing_template_decl;
9390 new_type = tsubst (TREE_TYPE (t), args, complain, in_decl);
9391 --processing_template_decl;
9392 if (new_type == error_mark_node)
9393 RETURN (error_mark_node);
9395 TREE_TYPE (r) = new_type;
9396 CLASSTYPE_TI_TEMPLATE (new_type) = r;
9397 DECL_TEMPLATE_RESULT (r) = TYPE_MAIN_DECL (new_type);
9398 DECL_TI_ARGS (r) = CLASSTYPE_TI_ARGS (new_type);
9399 DECL_CONTEXT (r) = TYPE_CONTEXT (new_type);
9404 ++processing_template_decl;
9405 new_decl = tsubst (decl, args, complain, in_decl);
9406 --processing_template_decl;
9407 if (new_decl == error_mark_node)
9408 RETURN (error_mark_node);
9410 DECL_TEMPLATE_RESULT (r) = new_decl;
9411 DECL_TI_TEMPLATE (new_decl) = r;
9412 TREE_TYPE (r) = TREE_TYPE (new_decl);
9413 DECL_TI_ARGS (r) = DECL_TI_ARGS (new_decl);
9414 DECL_CONTEXT (r) = DECL_CONTEXT (new_decl);
9417 SET_DECL_IMPLICIT_INSTANTIATION (r);
9418 DECL_TEMPLATE_INSTANTIATIONS (r) = NULL_TREE;
9419 DECL_TEMPLATE_SPECIALIZATIONS (r) = NULL_TREE;
9421 /* The template parameters for this new template are all the
9422 template parameters for the old template, except the
9423 outermost level of parameters. */
9424 DECL_TEMPLATE_PARMS (r)
9425 = tsubst_template_parms (DECL_TEMPLATE_PARMS (t), args,
9428 if (PRIMARY_TEMPLATE_P (t))
9429 DECL_PRIMARY_TEMPLATE (r) = r;
9431 if (TREE_CODE (decl) != TYPE_DECL)
9432 /* Record this non-type partial instantiation. */
9433 register_specialization (r, t,
9434 DECL_TI_ARGS (DECL_TEMPLATE_RESULT (r)),
9442 tree argvec = NULL_TREE;
9450 /* Nobody should be tsubst'ing into non-template functions. */
9451 gcc_assert (DECL_TEMPLATE_INFO (t) != NULL_TREE);
9453 if (TREE_CODE (DECL_TI_TEMPLATE (t)) == TEMPLATE_DECL)
9458 /* If T is not dependent, just return it. We have to
9459 increment PROCESSING_TEMPLATE_DECL because
9460 value_dependent_expression_p assumes that nothing is
9461 dependent when PROCESSING_TEMPLATE_DECL is zero. */
9462 ++processing_template_decl;
9463 dependent_p = value_dependent_expression_p (t);
9464 --processing_template_decl;
9468 /* Calculate the most general template of which R is a
9469 specialization, and the complete set of arguments used to
9471 gen_tmpl = most_general_template (DECL_TI_TEMPLATE (t));
9472 argvec = tsubst_template_args (DECL_TI_ARGS
9473 (DECL_TEMPLATE_RESULT
9474 (DECL_TI_TEMPLATE (t))),
9475 args, complain, in_decl);
9477 /* Check to see if we already have this specialization. */
9478 hash = hash_tmpl_and_args (gen_tmpl, argvec);
9479 spec = retrieve_specialization (gen_tmpl, argvec, hash);
9487 /* We can see more levels of arguments than parameters if
9488 there was a specialization of a member template, like
9491 template <class T> struct S { template <class U> void f(); }
9492 template <> template <class U> void S<int>::f(U);
9494 Here, we'll be substituting into the specialization,
9495 because that's where we can find the code we actually
9496 want to generate, but we'll have enough arguments for
9497 the most general template.
9499 We also deal with the peculiar case:
9501 template <class T> struct S {
9502 template <class U> friend void f();
9504 template <class U> void f() {}
9506 template void f<double>();
9508 Here, the ARGS for the instantiation of will be {int,
9509 double}. But, we only need as many ARGS as there are
9510 levels of template parameters in CODE_PATTERN. We are
9511 careful not to get fooled into reducing the ARGS in
9514 template <class T> struct S { template <class U> void f(U); }
9515 template <class T> template <> void S<T>::f(int) {}
9517 which we can spot because the pattern will be a
9518 specialization in this case. */
9519 args_depth = TMPL_ARGS_DEPTH (args);
9521 TMPL_PARMS_DEPTH (DECL_TEMPLATE_PARMS (DECL_TI_TEMPLATE (t)));
9522 if (args_depth > parms_depth
9523 && !DECL_TEMPLATE_SPECIALIZATION (t))
9524 args = get_innermost_template_args (args, parms_depth);
9528 /* This special case arises when we have something like this:
9530 template <class T> struct S {
9531 friend void f<int>(int, double);
9534 Here, the DECL_TI_TEMPLATE for the friend declaration
9535 will be an IDENTIFIER_NODE. We are being called from
9536 tsubst_friend_function, and we want only to create a
9537 new decl (R) with appropriate types so that we can call
9538 determine_specialization. */
9539 gen_tmpl = NULL_TREE;
9542 if (DECL_CLASS_SCOPE_P (t))
9544 if (DECL_NAME (t) == constructor_name (DECL_CONTEXT (t)))
9548 ctx = tsubst_aggr_type (DECL_CONTEXT (t), args,
9549 complain, t, /*entering_scope=*/1);
9554 ctx = DECL_CONTEXT (t);
9556 type = tsubst (TREE_TYPE (t), args, complain, in_decl);
9557 if (type == error_mark_node)
9558 RETURN (error_mark_node);
9560 /* We do NOT check for matching decls pushed separately at this
9561 point, as they may not represent instantiations of this
9562 template, and in any case are considered separate under the
9565 DECL_USE_TEMPLATE (r) = 0;
9566 TREE_TYPE (r) = type;
9567 /* Clear out the mangled name and RTL for the instantiation. */
9568 SET_DECL_ASSEMBLER_NAME (r, NULL_TREE);
9569 SET_DECL_RTL (r, NULL);
9570 /* Leave DECL_INITIAL set on deleted instantiations. */
9571 if (!DECL_DELETED_FN (r))
9572 DECL_INITIAL (r) = NULL_TREE;
9573 DECL_CONTEXT (r) = ctx;
9575 if (member && DECL_CONV_FN_P (r))
9576 /* Type-conversion operator. Reconstruct the name, in
9577 case it's the name of one of the template's parameters. */
9578 DECL_NAME (r) = mangle_conv_op_name_for_type (TREE_TYPE (type));
9580 DECL_ARGUMENTS (r) = tsubst (DECL_ARGUMENTS (t), args,
9582 DECL_RESULT (r) = NULL_TREE;
9584 TREE_STATIC (r) = 0;
9585 TREE_PUBLIC (r) = TREE_PUBLIC (t);
9586 DECL_EXTERNAL (r) = 1;
9587 /* If this is an instantiation of a function with internal
9588 linkage, we already know what object file linkage will be
9589 assigned to the instantiation. */
9590 DECL_INTERFACE_KNOWN (r) = !TREE_PUBLIC (r);
9591 DECL_DEFER_OUTPUT (r) = 0;
9592 DECL_CHAIN (r) = NULL_TREE;
9593 DECL_PENDING_INLINE_INFO (r) = 0;
9594 DECL_PENDING_INLINE_P (r) = 0;
9595 DECL_SAVED_TREE (r) = NULL_TREE;
9596 DECL_STRUCT_FUNCTION (r) = NULL;
9598 /* We'll re-clone as appropriate in instantiate_template. */
9599 DECL_CLONED_FUNCTION (r) = NULL_TREE;
9601 /* If we aren't complaining now, return on error before we register
9602 the specialization so that we'll complain eventually. */
9603 if ((complain & tf_error) == 0
9604 && IDENTIFIER_OPNAME_P (DECL_NAME (r))
9605 && !grok_op_properties (r, /*complain=*/false))
9606 RETURN (error_mark_node);
9608 /* Set up the DECL_TEMPLATE_INFO for R. There's no need to do
9609 this in the special friend case mentioned above where
9610 GEN_TMPL is NULL. */
9613 DECL_TEMPLATE_INFO (r)
9614 = build_template_info (gen_tmpl, argvec);
9615 SET_DECL_IMPLICIT_INSTANTIATION (r);
9616 register_specialization (r, gen_tmpl, argvec, false, hash);
9618 /* We're not supposed to instantiate default arguments
9619 until they are called, for a template. But, for a
9622 template <class T> void f ()
9623 { extern void g(int i = T()); }
9625 we should do the substitution when the template is
9626 instantiated. We handle the member function case in
9627 instantiate_class_template since the default arguments
9628 might refer to other members of the class. */
9630 && !PRIMARY_TEMPLATE_P (gen_tmpl)
9631 && !uses_template_parms (argvec))
9632 tsubst_default_arguments (r);
9635 DECL_TEMPLATE_INFO (r) = NULL_TREE;
9637 /* Copy the list of befriending classes. */
9638 for (friends = &DECL_BEFRIENDING_CLASSES (r);
9640 friends = &TREE_CHAIN (*friends))
9642 *friends = copy_node (*friends);
9643 TREE_VALUE (*friends) = tsubst (TREE_VALUE (*friends),
9648 if (DECL_CONSTRUCTOR_P (r) || DECL_DESTRUCTOR_P (r))
9650 maybe_retrofit_in_chrg (r);
9651 if (DECL_CONSTRUCTOR_P (r))
9652 grok_ctor_properties (ctx, r);
9653 /* If this is an instantiation of a member template, clone it.
9654 If it isn't, that'll be handled by
9655 clone_constructors_and_destructors. */
9656 if (PRIMARY_TEMPLATE_P (gen_tmpl))
9657 clone_function_decl (r, /*update_method_vec_p=*/0);
9659 else if ((complain & tf_error) != 0
9660 && IDENTIFIER_OPNAME_P (DECL_NAME (r))
9661 && !grok_op_properties (r, /*complain=*/true))
9662 RETURN (error_mark_node);
9664 if (DECL_FRIEND_P (t) && DECL_FRIEND_CONTEXT (t))
9665 SET_DECL_FRIEND_CONTEXT (r,
9666 tsubst (DECL_FRIEND_CONTEXT (t),
9667 args, complain, in_decl));
9669 /* Possibly limit visibility based on template args. */
9670 DECL_VISIBILITY (r) = VISIBILITY_DEFAULT;
9671 if (DECL_VISIBILITY_SPECIFIED (t))
9673 DECL_VISIBILITY_SPECIFIED (r) = 0;
9675 = remove_attribute ("visibility", DECL_ATTRIBUTES (r));
9677 determine_visibility (r);
9678 if (DECL_DEFAULTED_OUTSIDE_CLASS_P (r)
9679 && !processing_template_decl)
9680 defaulted_late_check (r);
9682 apply_late_template_attributes (&r, DECL_ATTRIBUTES (r), 0,
9683 args, complain, in_decl);
9689 tree type = NULL_TREE;
9691 tree expanded_types = NULL_TREE;
9692 tree prev_r = NULL_TREE;
9693 tree first_r = NULL_TREE;
9695 if (FUNCTION_PARAMETER_PACK_P (t))
9697 /* If there is a local specialization that isn't a
9698 parameter pack, it means that we're doing a "simple"
9699 substitution from inside tsubst_pack_expansion. Just
9700 return the local specialization (which will be a single
9702 tree spec = retrieve_local_specialization (t);
9704 && TREE_CODE (spec) == PARM_DECL
9705 && TREE_CODE (TREE_TYPE (spec)) != TYPE_PACK_EXPANSION)
9708 /* Expand the TYPE_PACK_EXPANSION that provides the types for
9709 the parameters in this function parameter pack. */
9710 expanded_types = tsubst_pack_expansion (TREE_TYPE (t), args,
9712 if (TREE_CODE (expanded_types) == TREE_VEC)
9714 len = TREE_VEC_LENGTH (expanded_types);
9716 /* Zero-length parameter packs are boring. Just substitute
9719 RETURN (tsubst (TREE_CHAIN (t), args, complain,
9724 /* All we did was update the type. Make a note of that. */
9725 type = expanded_types;
9726 expanded_types = NULL_TREE;
9730 /* Loop through all of the parameter's we'll build. When T is
9731 a function parameter pack, LEN is the number of expanded
9732 types in EXPANDED_TYPES; otherwise, LEN is 1. */
9734 for (i = 0; i < len; ++i)
9738 if (DECL_TEMPLATE_PARM_P (t))
9739 SET_DECL_TEMPLATE_PARM_P (r);
9741 /* An argument of a function parameter pack is not a parameter
9743 FUNCTION_PARAMETER_PACK_P (r) = false;
9746 /* We're on the Ith parameter of the function parameter
9749 /* Get the Ith type. */
9750 type = TREE_VEC_ELT (expanded_types, i);
9753 /* Rename the parameter to include the index. */
9755 make_ith_pack_parameter_name (DECL_NAME (r), i);
9758 /* We're dealing with a normal parameter. */
9759 type = tsubst (TREE_TYPE (t), args, complain, in_decl);
9761 type = type_decays_to (type);
9762 TREE_TYPE (r) = type;
9763 cp_apply_type_quals_to_decl (cp_type_quals (type), r);
9765 if (DECL_INITIAL (r))
9767 if (TREE_CODE (DECL_INITIAL (r)) != TEMPLATE_PARM_INDEX)
9768 DECL_INITIAL (r) = TREE_TYPE (r);
9770 DECL_INITIAL (r) = tsubst (DECL_INITIAL (r), args,
9774 DECL_CONTEXT (r) = NULL_TREE;
9776 if (!DECL_TEMPLATE_PARM_P (r))
9777 DECL_ARG_TYPE (r) = type_passed_as (type);
9779 apply_late_template_attributes (&r, DECL_ATTRIBUTES (r), 0,
9780 args, complain, in_decl);
9782 /* Keep track of the first new parameter we
9783 generate. That's what will be returned to the
9788 /* Build a proper chain of parameters when substituting
9789 into a function parameter pack. */
9791 DECL_CHAIN (prev_r) = r;
9795 DECL_CHAIN (r) = tsubst (DECL_CHAIN (t), args,
9796 complain, DECL_CHAIN (t));
9798 /* FIRST_R contains the start of the chain we've built. */
9808 type = tsubst (TREE_TYPE (t), args, complain, in_decl);
9809 if (type == error_mark_node)
9810 RETURN (error_mark_node);
9811 TREE_TYPE (r) = type;
9812 cp_apply_type_quals_to_decl (cp_type_quals (type), r);
9814 /* DECL_INITIAL gives the number of bits in a bit-field. */
9816 = tsubst_expr (DECL_INITIAL (t), args,
9818 /*integral_constant_expression_p=*/true);
9819 /* We don't have to set DECL_CONTEXT here; it is set by
9820 finish_member_declaration. */
9821 DECL_CHAIN (r) = NULL_TREE;
9822 if (VOID_TYPE_P (type))
9823 error ("instantiation of %q+D as type %qT", r, type);
9825 apply_late_template_attributes (&r, DECL_ATTRIBUTES (r), 0,
9826 args, complain, in_decl);
9831 /* We reach here only for member using decls. */
9832 if (DECL_DEPENDENT_P (t))
9834 r = do_class_using_decl
9835 (tsubst_copy (USING_DECL_SCOPE (t), args, complain, in_decl),
9836 tsubst_copy (DECL_NAME (t), args, complain, in_decl));
9838 r = error_mark_node;
9841 TREE_PROTECTED (r) = TREE_PROTECTED (t);
9842 TREE_PRIVATE (r) = TREE_PRIVATE (t);
9848 DECL_CHAIN (r) = NULL_TREE;
9855 tree argvec = NULL_TREE;
9856 tree gen_tmpl = NULL_TREE;
9858 tree tmpl = NULL_TREE;
9860 tree type = NULL_TREE;
9863 if (TREE_CODE (t) == TYPE_DECL
9864 && t == TYPE_MAIN_DECL (TREE_TYPE (t)))
9866 /* If this is the canonical decl, we don't have to
9867 mess with instantiations, and often we can't (for
9868 typename, template type parms and such). Note that
9869 TYPE_NAME is not correct for the above test if
9870 we've copied the type for a typedef. */
9871 type = tsubst (TREE_TYPE (t), args, complain, in_decl);
9872 if (type == error_mark_node)
9873 RETURN (error_mark_node);
9874 r = TYPE_NAME (type);
9878 /* Check to see if we already have the specialization we
9881 if (DECL_CLASS_SCOPE_P (t) || DECL_NAMESPACE_SCOPE_P (t))
9883 /* T is a static data member or namespace-scope entity.
9884 We have to substitute into namespace-scope variables
9885 (even though such entities are never templates) because
9888 template <class T> void f() { extern T t; }
9890 where the entity referenced is not known until
9891 instantiation time. */
9893 ctx = DECL_CONTEXT (t);
9894 if (DECL_CLASS_SCOPE_P (t))
9896 ctx = tsubst_aggr_type (ctx, args,
9898 in_decl, /*entering_scope=*/1);
9899 /* If CTX is unchanged, then T is in fact the
9900 specialization we want. That situation occurs when
9901 referencing a static data member within in its own
9902 class. We can use pointer equality, rather than
9903 same_type_p, because DECL_CONTEXT is always
9905 if (ctx == DECL_CONTEXT (t))
9911 tmpl = DECL_TI_TEMPLATE (t);
9912 gen_tmpl = most_general_template (tmpl);
9913 argvec = tsubst (DECL_TI_ARGS (t), args, complain, in_decl);
9914 hash = hash_tmpl_and_args (gen_tmpl, argvec);
9915 spec = retrieve_specialization (gen_tmpl, argvec, hash);
9920 /* A local variable. */
9922 /* Subsequent calls to pushdecl will fill this in. */
9924 spec = retrieve_local_specialization (t);
9926 /* If we already have the specialization we need, there is
9927 nothing more to do. */
9934 /* Create a new node for the specialization we need. */
9936 if (type == NULL_TREE)
9938 if (is_typedef_decl (t))
9939 type = DECL_ORIGINAL_TYPE (t);
9941 type = TREE_TYPE (t);
9942 if (TREE_CODE (t) == VAR_DECL && VAR_HAD_UNKNOWN_BOUND (t))
9943 type = strip_array_domain (type);
9944 type = tsubst (type, args, complain, in_decl);
9946 if (TREE_CODE (r) == VAR_DECL)
9948 /* Even if the original location is out of scope, the
9949 newly substituted one is not. */
9950 DECL_DEAD_FOR_LOCAL (r) = 0;
9951 DECL_INITIALIZED_P (r) = 0;
9952 DECL_TEMPLATE_INSTANTIATED (r) = 0;
9953 if (type == error_mark_node)
9954 RETURN (error_mark_node);
9955 if (TREE_CODE (type) == FUNCTION_TYPE)
9957 /* It may seem that this case cannot occur, since:
9962 declares a function, not a variable. However:
9965 template <typename T> void g() { T t; }
9966 template void g<f>();
9968 is an attempt to declare a variable with function
9970 error ("variable %qD has function type",
9971 /* R is not yet sufficiently initialized, so we
9972 just use its name. */
9974 RETURN (error_mark_node);
9976 type = complete_type (type);
9977 /* Wait until cp_finish_decl to set this again, to handle
9978 circular dependency (template/instantiate6.C). */
9979 DECL_INITIALIZED_BY_CONSTANT_EXPRESSION_P (r) = 0;
9980 type = check_var_type (DECL_NAME (r), type);
9982 if (DECL_HAS_VALUE_EXPR_P (t))
9984 tree ve = DECL_VALUE_EXPR (t);
9985 ve = tsubst_expr (ve, args, complain, in_decl,
9986 /*constant_expression_p=*/false);
9987 SET_DECL_VALUE_EXPR (r, ve);
9990 else if (DECL_SELF_REFERENCE_P (t))
9991 SET_DECL_SELF_REFERENCE_P (r);
9992 TREE_TYPE (r) = type;
9993 cp_apply_type_quals_to_decl (cp_type_quals (type), r);
9994 DECL_CONTEXT (r) = ctx;
9995 /* Clear out the mangled name and RTL for the instantiation. */
9996 SET_DECL_ASSEMBLER_NAME (r, NULL_TREE);
9997 if (CODE_CONTAINS_STRUCT (TREE_CODE (t), TS_DECL_WRTL))
9998 SET_DECL_RTL (r, NULL);
9999 /* The initializer must not be expanded until it is required;
10000 see [temp.inst]. */
10001 DECL_INITIAL (r) = NULL_TREE;
10002 if (CODE_CONTAINS_STRUCT (TREE_CODE (t), TS_DECL_WRTL))
10003 SET_DECL_RTL (r, NULL);
10004 DECL_SIZE (r) = DECL_SIZE_UNIT (r) = 0;
10005 if (TREE_CODE (r) == VAR_DECL)
10007 /* Possibly limit visibility based on template args. */
10008 DECL_VISIBILITY (r) = VISIBILITY_DEFAULT;
10009 if (DECL_VISIBILITY_SPECIFIED (t))
10011 DECL_VISIBILITY_SPECIFIED (r) = 0;
10012 DECL_ATTRIBUTES (r)
10013 = remove_attribute ("visibility", DECL_ATTRIBUTES (r));
10015 determine_visibility (r);
10020 /* A static data member declaration is always marked
10021 external when it is declared in-class, even if an
10022 initializer is present. We mimic the non-template
10023 processing here. */
10024 DECL_EXTERNAL (r) = 1;
10026 register_specialization (r, gen_tmpl, argvec, false, hash);
10027 DECL_TEMPLATE_INFO (r) = build_template_info (tmpl, argvec);
10028 SET_DECL_IMPLICIT_INSTANTIATION (r);
10030 else if (cp_unevaluated_operand)
10032 /* We're substituting this var in a decltype outside of its
10033 scope, such as for a lambda return type. Don't add it to
10034 local_specializations, do perform auto deduction. */
10035 tree auto_node = type_uses_auto (type);
10037 = tsubst_expr (DECL_INITIAL (t), args, complain, in_decl,
10038 /*constant_expression_p=*/false);
10040 if (auto_node && init)
10042 init = resolve_nondeduced_context (init);
10043 if (describable_type (init))
10045 type = do_auto_deduction (type, init, auto_node);
10046 TREE_TYPE (r) = type;
10051 register_local_specialization (r, t);
10053 DECL_CHAIN (r) = NULL_TREE;
10055 apply_late_template_attributes (&r, DECL_ATTRIBUTES (r),
10057 args, complain, in_decl);
10059 /* Preserve a typedef that names a type. */
10060 if (is_typedef_decl (r))
10062 DECL_ORIGINAL_TYPE (r) = NULL_TREE;
10063 set_underlying_type (r);
10066 layout_decl (r, 0);
10071 gcc_unreachable ();
10076 /* Restore the file and line information. */
10077 input_location = saved_loc;
10082 /* Substitute into the ARG_TYPES of a function type. */
10085 tsubst_arg_types (tree arg_types,
10087 tsubst_flags_t complain,
10090 tree remaining_arg_types;
10091 tree type = NULL_TREE;
10093 tree expanded_args = NULL_TREE;
10096 if (!arg_types || arg_types == void_list_node)
10099 remaining_arg_types = tsubst_arg_types (TREE_CHAIN (arg_types),
10100 args, complain, in_decl);
10101 if (remaining_arg_types == error_mark_node)
10102 return error_mark_node;
10104 if (PACK_EXPANSION_P (TREE_VALUE (arg_types)))
10106 /* For a pack expansion, perform substitution on the
10107 entire expression. Later on, we'll handle the arguments
10109 expanded_args = tsubst_pack_expansion (TREE_VALUE (arg_types),
10110 args, complain, in_decl);
10112 if (TREE_CODE (expanded_args) == TREE_VEC)
10113 /* So that we'll spin through the parameters, one by one. */
10114 i = TREE_VEC_LENGTH (expanded_args);
10117 /* We only partially substituted into the parameter
10118 pack. Our type is TYPE_PACK_EXPANSION. */
10119 type = expanded_args;
10120 expanded_args = NULL_TREE;
10128 type = TREE_VEC_ELT (expanded_args, i);
10130 type = tsubst (TREE_VALUE (arg_types), args, complain, in_decl);
10132 if (type == error_mark_node)
10133 return error_mark_node;
10134 if (VOID_TYPE_P (type))
10136 if (complain & tf_error)
10138 error ("invalid parameter type %qT", type);
10140 error ("in declaration %q+D", in_decl);
10142 return error_mark_node;
10145 /* Do array-to-pointer, function-to-pointer conversion, and ignore
10146 top-level qualifiers as required. */
10147 type = TYPE_MAIN_VARIANT (type_decays_to (type));
10149 /* We do not substitute into default arguments here. The standard
10150 mandates that they be instantiated only when needed, which is
10151 done in build_over_call. */
10152 default_arg = TREE_PURPOSE (arg_types);
10154 if (default_arg && TREE_CODE (default_arg) == DEFAULT_ARG)
10156 /* We've instantiated a template before its default arguments
10157 have been parsed. This can happen for a nested template
10158 class, and is not an error unless we require the default
10159 argument in a call of this function. */
10160 remaining_arg_types =
10161 tree_cons (default_arg, type, remaining_arg_types);
10162 VEC_safe_push (tree, gc, DEFARG_INSTANTIATIONS (default_arg),
10163 remaining_arg_types);
10166 remaining_arg_types =
10167 hash_tree_cons (default_arg, type, remaining_arg_types);
10170 return remaining_arg_types;
10173 /* Substitute into a FUNCTION_TYPE or METHOD_TYPE. This routine does
10174 *not* handle the exception-specification for FNTYPE, because the
10175 initial substitution of explicitly provided template parameters
10176 during argument deduction forbids substitution into the
10177 exception-specification:
10181 All references in the function type of the function template to the
10182 corresponding template parameters are replaced by the specified tem-
10183 plate argument values. If a substitution in a template parameter or
10184 in the function type of the function template results in an invalid
10185 type, type deduction fails. [Note: The equivalent substitution in
10186 exception specifications is done only when the function is instanti-
10187 ated, at which point a program is ill-formed if the substitution
10188 results in an invalid type.] */
10191 tsubst_function_type (tree t,
10193 tsubst_flags_t complain,
10200 /* The TYPE_CONTEXT is not used for function/method types. */
10201 gcc_assert (TYPE_CONTEXT (t) == NULL_TREE);
10203 /* Substitute the return type. */
10204 return_type = tsubst (TREE_TYPE (t), args, complain, in_decl);
10205 if (return_type == error_mark_node)
10206 return error_mark_node;
10207 /* The standard does not presently indicate that creation of a
10208 function type with an invalid return type is a deduction failure.
10209 However, that is clearly analogous to creating an array of "void"
10210 or a reference to a reference. This is core issue #486. */
10211 if (TREE_CODE (return_type) == ARRAY_TYPE
10212 || TREE_CODE (return_type) == FUNCTION_TYPE)
10214 if (complain & tf_error)
10216 if (TREE_CODE (return_type) == ARRAY_TYPE)
10217 error ("function returning an array");
10219 error ("function returning a function");
10221 return error_mark_node;
10224 /* Substitute the argument types. */
10225 arg_types = tsubst_arg_types (TYPE_ARG_TYPES (t), args,
10226 complain, in_decl);
10227 if (arg_types == error_mark_node)
10228 return error_mark_node;
10230 /* Construct a new type node and return it. */
10231 if (TREE_CODE (t) == FUNCTION_TYPE)
10233 fntype = build_function_type (return_type, arg_types);
10234 fntype = apply_memfn_quals (fntype, type_memfn_quals (t));
10238 tree r = TREE_TYPE (TREE_VALUE (arg_types));
10239 if (! MAYBE_CLASS_TYPE_P (r))
10243 Type deduction may fail for any of the following
10246 -- Attempting to create "pointer to member of T" when T
10247 is not a class type. */
10248 if (complain & tf_error)
10249 error ("creating pointer to member function of non-class type %qT",
10251 return error_mark_node;
10254 fntype = build_method_type_directly (r, return_type,
10255 TREE_CHAIN (arg_types));
10257 fntype = cp_build_type_attribute_variant (fntype, TYPE_ATTRIBUTES (t));
10262 /* FNTYPE is a FUNCTION_TYPE or METHOD_TYPE. Substitute the template
10263 ARGS into that specification, and return the substituted
10264 specification. If there is no specification, return NULL_TREE. */
10267 tsubst_exception_specification (tree fntype,
10269 tsubst_flags_t complain,
10275 specs = TYPE_RAISES_EXCEPTIONS (fntype);
10276 new_specs = NULL_TREE;
10277 if (specs && TREE_PURPOSE (specs))
10279 /* A noexcept-specifier. */
10280 new_specs = tsubst_copy_and_build
10281 (TREE_PURPOSE (specs), args, complain, in_decl, /*function_p=*/false,
10282 /*integral_constant_expression_p=*/true);
10283 new_specs = build_noexcept_spec (new_specs, complain);
10287 if (! TREE_VALUE (specs))
10294 tree expanded_specs = NULL_TREE;
10296 if (PACK_EXPANSION_P (TREE_VALUE (specs)))
10298 /* Expand the pack expansion type. */
10299 expanded_specs = tsubst_pack_expansion (TREE_VALUE (specs),
10303 if (expanded_specs == error_mark_node)
10304 return error_mark_node;
10305 else if (TREE_CODE (expanded_specs) == TREE_VEC)
10306 len = TREE_VEC_LENGTH (expanded_specs);
10309 /* We're substituting into a member template, so
10310 we got a TYPE_PACK_EXPANSION back. Add that
10311 expansion and move on. */
10312 gcc_assert (TREE_CODE (expanded_specs)
10313 == TYPE_PACK_EXPANSION);
10314 new_specs = add_exception_specifier (new_specs,
10317 specs = TREE_CHAIN (specs);
10322 for (i = 0; i < len; ++i)
10324 if (expanded_specs)
10325 spec = TREE_VEC_ELT (expanded_specs, i);
10327 spec = tsubst (TREE_VALUE (specs), args, complain, in_decl);
10328 if (spec == error_mark_node)
10330 new_specs = add_exception_specifier (new_specs, spec,
10334 specs = TREE_CHAIN (specs);
10340 /* Take the tree structure T and replace template parameters used
10341 therein with the argument vector ARGS. IN_DECL is an associated
10342 decl for diagnostics. If an error occurs, returns ERROR_MARK_NODE.
10343 Issue error and warning messages under control of COMPLAIN. Note
10344 that we must be relatively non-tolerant of extensions here, in
10345 order to preserve conformance; if we allow substitutions that
10346 should not be allowed, we may allow argument deductions that should
10347 not succeed, and therefore report ambiguous overload situations
10348 where there are none. In theory, we could allow the substitution,
10349 but indicate that it should have failed, and allow our caller to
10350 make sure that the right thing happens, but we don't try to do this
10353 This function is used for dealing with types, decls and the like;
10354 for expressions, use tsubst_expr or tsubst_copy. */
10357 tsubst (tree t, tree args, tsubst_flags_t complain, tree in_decl)
10359 enum tree_code code;
10362 if (t == NULL_TREE || t == error_mark_node
10363 || t == integer_type_node
10364 || t == void_type_node
10365 || t == char_type_node
10366 || t == unknown_type_node
10367 || TREE_CODE (t) == NAMESPACE_DECL
10368 || TREE_CODE (t) == TRANSLATION_UNIT_DECL)
10372 return tsubst_decl (t, args, complain);
10374 if (args == NULL_TREE)
10377 code = TREE_CODE (t);
10379 if (code == IDENTIFIER_NODE)
10380 type = IDENTIFIER_TYPE_VALUE (t);
10382 type = TREE_TYPE (t);
10384 gcc_assert (type != unknown_type_node);
10386 /* Reuse typedefs. We need to do this to handle dependent attributes,
10387 such as attribute aligned. */
10389 && typedef_variant_p (t))
10391 tree decl = TYPE_NAME (t);
10393 if (DECL_CLASS_SCOPE_P (decl)
10394 && CLASSTYPE_TEMPLATE_INFO (DECL_CONTEXT (decl))
10395 && uses_template_parms (DECL_CONTEXT (decl)))
10397 tree tmpl = most_general_template (DECL_TI_TEMPLATE (decl));
10398 tree gen_args = tsubst (DECL_TI_ARGS (decl), args, complain, in_decl);
10399 r = retrieve_specialization (tmpl, gen_args, 0);
10401 else if (DECL_FUNCTION_SCOPE_P (decl)
10402 && DECL_TEMPLATE_INFO (DECL_CONTEXT (decl))
10403 && uses_template_parms (DECL_TI_ARGS (DECL_CONTEXT (decl))))
10404 r = retrieve_local_specialization (decl);
10406 /* The typedef is from a non-template context. */
10412 r = cp_build_qualified_type_real
10413 (r, cp_type_quals (t) | cp_type_quals (r),
10414 complain | tf_ignore_bad_quals);
10417 /* Else we must be instantiating the typedef, so fall through. */
10421 && code != TYPENAME_TYPE
10422 && code != TEMPLATE_TYPE_PARM
10423 && code != IDENTIFIER_NODE
10424 && code != FUNCTION_TYPE
10425 && code != METHOD_TYPE)
10426 type = tsubst (type, args, complain, in_decl);
10427 if (type == error_mark_node)
10428 return error_mark_node;
10434 case ENUMERAL_TYPE:
10435 return tsubst_aggr_type (t, args, complain, in_decl,
10436 /*entering_scope=*/0);
10439 case IDENTIFIER_NODE:
10450 if (t == integer_type_node)
10453 if (TREE_CODE (TYPE_MIN_VALUE (t)) == INTEGER_CST
10454 && TREE_CODE (TYPE_MAX_VALUE (t)) == INTEGER_CST)
10458 tree max, omax = TREE_OPERAND (TYPE_MAX_VALUE (t), 0);
10460 max = tsubst_expr (omax, args, complain, in_decl,
10461 /*integral_constant_expression_p=*/false);
10463 /* Fix up type of the magic NOP_EXPR with TREE_SIDE_EFFECTS if
10465 if (TREE_CODE (max) == NOP_EXPR
10466 && TREE_SIDE_EFFECTS (omax)
10467 && !TREE_TYPE (max))
10468 TREE_TYPE (max) = TREE_TYPE (TREE_OPERAND (max, 0));
10470 /* If we're in a partial instantiation, preserve the magic NOP_EXPR
10471 with TREE_SIDE_EFFECTS that indicates this is not an integral
10472 constant expression. */
10473 if (processing_template_decl
10474 && TREE_SIDE_EFFECTS (omax) && TREE_CODE (omax) == NOP_EXPR)
10476 gcc_assert (TREE_CODE (max) == NOP_EXPR);
10477 TREE_SIDE_EFFECTS (max) = 1;
10480 return compute_array_index_type (NULL_TREE, max, complain);
10483 case TEMPLATE_TYPE_PARM:
10484 case TEMPLATE_TEMPLATE_PARM:
10485 case BOUND_TEMPLATE_TEMPLATE_PARM:
10486 case TEMPLATE_PARM_INDEX:
10491 tree arg = NULL_TREE;
10495 gcc_assert (TREE_VEC_LENGTH (args) > 0);
10496 template_parm_level_and_index (t, &level, &idx);
10498 levels = TMPL_ARGS_DEPTH (args);
10499 if (level <= levels)
10501 arg = TMPL_ARG (args, level, idx);
10503 if (arg && TREE_CODE (arg) == ARGUMENT_PACK_SELECT)
10504 /* See through ARGUMENT_PACK_SELECT arguments. */
10505 arg = ARGUMENT_PACK_SELECT_ARG (arg);
10508 if (arg == error_mark_node)
10509 return error_mark_node;
10510 else if (arg != NULL_TREE)
10512 if (ARGUMENT_PACK_P (arg))
10513 /* If ARG is an argument pack, we don't actually want to
10514 perform a substitution here, because substitutions
10515 for argument packs are only done
10516 element-by-element. We can get to this point when
10517 substituting the type of a non-type template
10518 parameter pack, when that type actually contains
10519 template parameter packs from an outer template, e.g.,
10521 template<typename... Types> struct A {
10522 template<Types... Values> struct B { };
10526 if (code == TEMPLATE_TYPE_PARM)
10529 gcc_assert (TYPE_P (arg));
10531 quals = cp_type_quals (arg) | cp_type_quals (t);
10533 return cp_build_qualified_type_real
10534 (arg, quals, complain | tf_ignore_bad_quals);
10536 else if (code == BOUND_TEMPLATE_TEMPLATE_PARM)
10538 /* We are processing a type constructed from a
10539 template template parameter. */
10540 tree argvec = tsubst (TYPE_TI_ARGS (t),
10541 args, complain, in_decl);
10542 if (argvec == error_mark_node)
10543 return error_mark_node;
10545 /* We can get a TEMPLATE_TEMPLATE_PARM here when we
10546 are resolving nested-types in the signature of a
10547 member function templates. Otherwise ARG is a
10548 TEMPLATE_DECL and is the real template to be
10550 if (TREE_CODE (arg) == TEMPLATE_TEMPLATE_PARM)
10551 arg = TYPE_NAME (arg);
10553 r = lookup_template_class (arg,
10555 DECL_CONTEXT (arg),
10556 /*entering_scope=*/0,
10558 return cp_build_qualified_type_real
10559 (r, cp_type_quals (t), complain);
10562 /* TEMPLATE_TEMPLATE_PARM or TEMPLATE_PARM_INDEX. */
10563 return unshare_expr (arg);
10567 /* This can happen during the attempted tsubst'ing in
10568 unify. This means that we don't yet have any information
10569 about the template parameter in question. */
10572 /* If we get here, we must have been looking at a parm for a
10573 more deeply nested template. Make a new version of this
10574 template parameter, but with a lower level. */
10577 case TEMPLATE_TYPE_PARM:
10578 case TEMPLATE_TEMPLATE_PARM:
10579 case BOUND_TEMPLATE_TEMPLATE_PARM:
10580 if (cp_type_quals (t))
10582 r = tsubst (TYPE_MAIN_VARIANT (t), args, complain, in_decl);
10583 r = cp_build_qualified_type_real
10584 (r, cp_type_quals (t),
10585 complain | (code == TEMPLATE_TYPE_PARM
10586 ? tf_ignore_bad_quals : 0));
10591 TEMPLATE_TYPE_PARM_INDEX (r)
10592 = reduce_template_parm_level (TEMPLATE_TYPE_PARM_INDEX (t),
10593 r, levels, args, complain);
10594 TYPE_STUB_DECL (r) = TYPE_NAME (r) = TEMPLATE_TYPE_DECL (r);
10595 TYPE_MAIN_VARIANT (r) = r;
10596 TYPE_POINTER_TO (r) = NULL_TREE;
10597 TYPE_REFERENCE_TO (r) = NULL_TREE;
10599 if (TREE_CODE (r) == TEMPLATE_TEMPLATE_PARM)
10600 /* We have reduced the level of the template
10601 template parameter, but not the levels of its
10602 template parameters, so canonical_type_parameter
10603 will not be able to find the canonical template
10604 template parameter for this level. Thus, we
10605 require structural equality checking to compare
10606 TEMPLATE_TEMPLATE_PARMs. */
10607 SET_TYPE_STRUCTURAL_EQUALITY (r);
10608 else if (TYPE_STRUCTURAL_EQUALITY_P (t))
10609 SET_TYPE_STRUCTURAL_EQUALITY (r);
10611 TYPE_CANONICAL (r) = canonical_type_parameter (r);
10613 if (code == BOUND_TEMPLATE_TEMPLATE_PARM)
10615 tree argvec = tsubst (TYPE_TI_ARGS (t), args,
10616 complain, in_decl);
10617 if (argvec == error_mark_node)
10618 return error_mark_node;
10620 TEMPLATE_TEMPLATE_PARM_TEMPLATE_INFO (r)
10621 = build_template_info (TYPE_TI_TEMPLATE (t), argvec);
10626 case TEMPLATE_PARM_INDEX:
10627 r = reduce_template_parm_level (t, type, levels, args, complain);
10631 gcc_unreachable ();
10639 tree purpose, value, chain;
10641 if (t == void_list_node)
10644 purpose = TREE_PURPOSE (t);
10647 purpose = tsubst (purpose, args, complain, in_decl);
10648 if (purpose == error_mark_node)
10649 return error_mark_node;
10651 value = TREE_VALUE (t);
10654 value = tsubst (value, args, complain, in_decl);
10655 if (value == error_mark_node)
10656 return error_mark_node;
10658 chain = TREE_CHAIN (t);
10659 if (chain && chain != void_type_node)
10661 chain = tsubst (chain, args, complain, in_decl);
10662 if (chain == error_mark_node)
10663 return error_mark_node;
10665 if (purpose == TREE_PURPOSE (t)
10666 && value == TREE_VALUE (t)
10667 && chain == TREE_CHAIN (t))
10669 return hash_tree_cons (purpose, value, chain);
10673 /* We should never be tsubsting a binfo. */
10674 gcc_unreachable ();
10677 /* A vector of template arguments. */
10678 gcc_assert (!type);
10679 return tsubst_template_args (t, args, complain, in_decl);
10682 case REFERENCE_TYPE:
10684 if (type == TREE_TYPE (t) && TREE_CODE (type) != METHOD_TYPE)
10689 Type deduction may fail for any of the following
10692 -- Attempting to create a pointer to reference type.
10693 -- Attempting to create a reference to a reference type or
10694 a reference to void.
10696 Core issue 106 says that creating a reference to a reference
10697 during instantiation is no longer a cause for failure. We
10698 only enforce this check in strict C++98 mode. */
10699 if ((TREE_CODE (type) == REFERENCE_TYPE
10700 && (((cxx_dialect == cxx98) && flag_iso) || code != REFERENCE_TYPE))
10701 || (code == REFERENCE_TYPE && TREE_CODE (type) == VOID_TYPE))
10703 static location_t last_loc;
10705 /* We keep track of the last time we issued this error
10706 message to avoid spewing a ton of messages during a
10707 single bad template instantiation. */
10708 if (complain & tf_error
10709 && last_loc != input_location)
10711 if (TREE_CODE (type) == VOID_TYPE)
10712 error ("forming reference to void");
10713 else if (code == POINTER_TYPE)
10714 error ("forming pointer to reference type %qT", type);
10716 error ("forming reference to reference type %qT", type);
10717 last_loc = input_location;
10720 return error_mark_node;
10722 else if (code == POINTER_TYPE)
10724 r = build_pointer_type (type);
10725 if (TREE_CODE (type) == METHOD_TYPE)
10726 r = build_ptrmemfunc_type (r);
10728 else if (TREE_CODE (type) == REFERENCE_TYPE)
10729 /* In C++0x, during template argument substitution, when there is an
10730 attempt to create a reference to a reference type, reference
10731 collapsing is applied as described in [14.3.1/4 temp.arg.type]:
10733 "If a template-argument for a template-parameter T names a type
10734 that is a reference to a type A, an attempt to create the type
10735 'lvalue reference to cv T' creates the type 'lvalue reference to
10736 A,' while an attempt to create the type type rvalue reference to
10737 cv T' creates the type T"
10739 r = cp_build_reference_type
10741 TYPE_REF_IS_RVALUE (t) && TYPE_REF_IS_RVALUE (type));
10743 r = cp_build_reference_type (type, TYPE_REF_IS_RVALUE (t));
10744 r = cp_build_qualified_type_real (r, cp_type_quals (t), complain);
10746 if (r != error_mark_node)
10747 /* Will this ever be needed for TYPE_..._TO values? */
10754 r = tsubst (TYPE_OFFSET_BASETYPE (t), args, complain, in_decl);
10755 if (r == error_mark_node || !MAYBE_CLASS_TYPE_P (r))
10759 Type deduction may fail for any of the following
10762 -- Attempting to create "pointer to member of T" when T
10763 is not a class type. */
10764 if (complain & tf_error)
10765 error ("creating pointer to member of non-class type %qT", r);
10766 return error_mark_node;
10768 if (TREE_CODE (type) == REFERENCE_TYPE)
10770 if (complain & tf_error)
10771 error ("creating pointer to member reference type %qT", type);
10772 return error_mark_node;
10774 if (TREE_CODE (type) == VOID_TYPE)
10776 if (complain & tf_error)
10777 error ("creating pointer to member of type void");
10778 return error_mark_node;
10780 gcc_assert (TREE_CODE (type) != METHOD_TYPE);
10781 if (TREE_CODE (type) == FUNCTION_TYPE)
10783 /* The type of the implicit object parameter gets its
10784 cv-qualifiers from the FUNCTION_TYPE. */
10786 tree method_type = build_memfn_type (type, r, type_memfn_quals (type));
10787 memptr = build_ptrmemfunc_type (build_pointer_type (method_type));
10788 return cp_build_qualified_type_real (memptr, cp_type_quals (t),
10792 return cp_build_qualified_type_real (build_ptrmem_type (r, type),
10796 case FUNCTION_TYPE:
10801 fntype = tsubst_function_type (t, args, complain, in_decl);
10802 if (fntype == error_mark_node)
10803 return error_mark_node;
10805 /* Substitute the exception specification. */
10806 specs = tsubst_exception_specification (t, args, complain,
10808 if (specs == error_mark_node)
10809 return error_mark_node;
10811 fntype = build_exception_variant (fntype, specs);
10816 tree domain = tsubst (TYPE_DOMAIN (t), args, complain, in_decl);
10817 if (domain == error_mark_node)
10818 return error_mark_node;
10820 /* As an optimization, we avoid regenerating the array type if
10821 it will obviously be the same as T. */
10822 if (type == TREE_TYPE (t) && domain == TYPE_DOMAIN (t))
10825 /* These checks should match the ones in grokdeclarator.
10829 The deduction may fail for any of the following reasons:
10831 -- Attempting to create an array with an element type that
10832 is void, a function type, or a reference type, or [DR337]
10833 an abstract class type. */
10834 if (TREE_CODE (type) == VOID_TYPE
10835 || TREE_CODE (type) == FUNCTION_TYPE
10836 || TREE_CODE (type) == REFERENCE_TYPE)
10838 if (complain & tf_error)
10839 error ("creating array of %qT", type);
10840 return error_mark_node;
10842 if (CLASS_TYPE_P (type) && CLASSTYPE_PURE_VIRTUALS (type))
10844 if (complain & tf_error)
10845 error ("creating array of %qT, which is an abstract class type",
10847 return error_mark_node;
10850 r = build_cplus_array_type (type, domain);
10852 if (TYPE_USER_ALIGN (t))
10854 TYPE_ALIGN (r) = TYPE_ALIGN (t);
10855 TYPE_USER_ALIGN (r) = 1;
10861 case TYPENAME_TYPE:
10863 tree ctx = tsubst_aggr_type (TYPE_CONTEXT (t), args, complain,
10864 in_decl, /*entering_scope=*/1);
10865 tree f = tsubst_copy (TYPENAME_TYPE_FULLNAME (t), args,
10866 complain, in_decl);
10868 if (ctx == error_mark_node || f == error_mark_node)
10869 return error_mark_node;
10871 if (!MAYBE_CLASS_TYPE_P (ctx))
10873 if (complain & tf_error)
10874 error ("%qT is not a class, struct, or union type", ctx);
10875 return error_mark_node;
10877 else if (!uses_template_parms (ctx) && !TYPE_BEING_DEFINED (ctx))
10879 /* Normally, make_typename_type does not require that the CTX
10880 have complete type in order to allow things like:
10882 template <class T> struct S { typename S<T>::X Y; };
10884 But, such constructs have already been resolved by this
10885 point, so here CTX really should have complete type, unless
10886 it's a partial instantiation. */
10887 ctx = complete_type (ctx);
10888 if (!COMPLETE_TYPE_P (ctx))
10890 if (complain & tf_error)
10891 cxx_incomplete_type_error (NULL_TREE, ctx);
10892 return error_mark_node;
10896 f = make_typename_type (ctx, f, typename_type,
10897 (complain & tf_error) | tf_keep_type_decl);
10898 if (f == error_mark_node)
10900 if (TREE_CODE (f) == TYPE_DECL)
10902 complain |= tf_ignore_bad_quals;
10906 if (TREE_CODE (f) != TYPENAME_TYPE)
10908 if (TYPENAME_IS_ENUM_P (t) && TREE_CODE (f) != ENUMERAL_TYPE)
10909 error ("%qT resolves to %qT, which is not an enumeration type",
10911 else if (TYPENAME_IS_CLASS_P (t) && !CLASS_TYPE_P (f))
10912 error ("%qT resolves to %qT, which is is not a class type",
10916 return cp_build_qualified_type_real
10917 (f, cp_type_quals (f) | cp_type_quals (t), complain);
10920 case UNBOUND_CLASS_TEMPLATE:
10922 tree ctx = tsubst_aggr_type (TYPE_CONTEXT (t), args, complain,
10923 in_decl, /*entering_scope=*/1);
10924 tree name = TYPE_IDENTIFIER (t);
10925 tree parm_list = DECL_TEMPLATE_PARMS (TYPE_NAME (t));
10927 if (ctx == error_mark_node || name == error_mark_node)
10928 return error_mark_node;
10931 parm_list = tsubst_template_parms (parm_list, args, complain);
10932 return make_unbound_class_template (ctx, name, parm_list, complain);
10939 ++cp_unevaluated_operand;
10940 ++c_inhibit_evaluation_warnings;
10942 type = tsubst_expr (TYPEOF_TYPE_EXPR (t), args,
10944 /*integral_constant_expression_p=*/false);
10946 --cp_unevaluated_operand;
10947 --c_inhibit_evaluation_warnings;
10949 type = finish_typeof (type);
10950 return cp_build_qualified_type_real (type,
10952 | cp_type_quals (type),
10956 case DECLTYPE_TYPE:
10960 ++cp_unevaluated_operand;
10961 ++c_inhibit_evaluation_warnings;
10963 type = tsubst_expr (DECLTYPE_TYPE_EXPR (t), args,
10965 /*integral_constant_expression_p=*/false);
10967 --cp_unevaluated_operand;
10968 --c_inhibit_evaluation_warnings;
10970 if (DECLTYPE_FOR_LAMBDA_CAPTURE (t))
10971 type = lambda_capture_field_type (type);
10972 else if (DECLTYPE_FOR_LAMBDA_RETURN (t))
10973 type = lambda_return_type (type);
10975 type = finish_decltype_type
10976 (type, DECLTYPE_TYPE_ID_EXPR_OR_MEMBER_ACCESS_P (t));
10977 return cp_build_qualified_type_real (type,
10979 | cp_type_quals (type),
10983 case TYPE_ARGUMENT_PACK:
10984 case NONTYPE_ARGUMENT_PACK:
10986 tree r = TYPE_P (t) ? cxx_make_type (code) : make_node (code);
10988 tsubst_template_args (ARGUMENT_PACK_ARGS (t),
10992 SET_ARGUMENT_PACK_ARGS (r, packed_out);
10994 /* For template nontype argument packs, also substitute into
10996 if (code == NONTYPE_ARGUMENT_PACK)
10997 TREE_TYPE (r) = tsubst (TREE_TYPE (t), args, complain, in_decl);
11015 /* We should use one of the expression tsubsts for these codes. */
11016 gcc_unreachable ();
11019 sorry ("use of %qs in template", tree_code_name [(int) code]);
11020 return error_mark_node;
11024 /* Like tsubst_expr for a BASELINK. OBJECT_TYPE, if non-NULL, is the
11025 type of the expression on the left-hand side of the "." or "->"
11029 tsubst_baselink (tree baselink, tree object_type,
11030 tree args, tsubst_flags_t complain, tree in_decl)
11033 tree qualifying_scope;
11036 tree template_args = 0;
11037 bool template_id_p = false;
11039 /* A baselink indicates a function from a base class. Both the
11040 BASELINK_ACCESS_BINFO and the base class referenced may
11041 indicate bases of the template class, rather than the
11042 instantiated class. In addition, lookups that were not
11043 ambiguous before may be ambiguous now. Therefore, we perform
11044 the lookup again. */
11045 qualifying_scope = BINFO_TYPE (BASELINK_ACCESS_BINFO (baselink));
11046 qualifying_scope = tsubst (qualifying_scope, args,
11047 complain, in_decl);
11048 fns = BASELINK_FUNCTIONS (baselink);
11049 optype = tsubst (BASELINK_OPTYPE (baselink), args, complain, in_decl);
11050 if (TREE_CODE (fns) == TEMPLATE_ID_EXPR)
11052 template_id_p = true;
11053 template_args = TREE_OPERAND (fns, 1);
11054 fns = TREE_OPERAND (fns, 0);
11056 template_args = tsubst_template_args (template_args, args,
11057 complain, in_decl);
11059 name = DECL_NAME (get_first_fn (fns));
11060 if (IDENTIFIER_TYPENAME_P (name))
11061 name = mangle_conv_op_name_for_type (optype);
11062 baselink = lookup_fnfields (qualifying_scope, name, /*protect=*/1);
11064 return error_mark_node;
11066 /* If lookup found a single function, mark it as used at this
11067 point. (If it lookup found multiple functions the one selected
11068 later by overload resolution will be marked as used at that
11070 if (BASELINK_P (baselink))
11071 fns = BASELINK_FUNCTIONS (baselink);
11072 if (!template_id_p && !really_overloaded_fn (fns))
11073 mark_used (OVL_CURRENT (fns));
11075 /* Add back the template arguments, if present. */
11076 if (BASELINK_P (baselink) && template_id_p)
11077 BASELINK_FUNCTIONS (baselink)
11078 = build_nt (TEMPLATE_ID_EXPR,
11079 BASELINK_FUNCTIONS (baselink),
11081 /* Update the conversion operator type. */
11082 BASELINK_OPTYPE (baselink) = optype;
11085 object_type = current_class_type;
11086 return adjust_result_of_qualified_name_lookup (baselink,
11091 /* Like tsubst_expr for a SCOPE_REF, given by QUALIFIED_ID. DONE is
11092 true if the qualified-id will be a postfix-expression in-and-of
11093 itself; false if more of the postfix-expression follows the
11094 QUALIFIED_ID. ADDRESS_P is true if the qualified-id is the operand
11098 tsubst_qualified_id (tree qualified_id, tree args,
11099 tsubst_flags_t complain, tree in_decl,
11100 bool done, bool address_p)
11106 tree template_args;
11108 gcc_assert (TREE_CODE (qualified_id) == SCOPE_REF);
11110 /* Figure out what name to look up. */
11111 name = TREE_OPERAND (qualified_id, 1);
11112 if (TREE_CODE (name) == TEMPLATE_ID_EXPR)
11114 is_template = true;
11115 template_args = TREE_OPERAND (name, 1);
11117 template_args = tsubst_template_args (template_args, args,
11118 complain, in_decl);
11119 name = TREE_OPERAND (name, 0);
11123 is_template = false;
11124 template_args = NULL_TREE;
11127 /* Substitute into the qualifying scope. When there are no ARGS, we
11128 are just trying to simplify a non-dependent expression. In that
11129 case the qualifying scope may be dependent, and, in any case,
11130 substituting will not help. */
11131 scope = TREE_OPERAND (qualified_id, 0);
11134 scope = tsubst (scope, args, complain, in_decl);
11135 expr = tsubst_copy (name, args, complain, in_decl);
11140 if (dependent_scope_p (scope))
11141 return build_qualified_name (NULL_TREE, scope, expr,
11142 QUALIFIED_NAME_IS_TEMPLATE (qualified_id));
11144 if (!BASELINK_P (name) && !DECL_P (expr))
11146 if (TREE_CODE (expr) == BIT_NOT_EXPR)
11148 /* A BIT_NOT_EXPR is used to represent a destructor. */
11149 if (!check_dtor_name (scope, TREE_OPERAND (expr, 0)))
11151 error ("qualifying type %qT does not match destructor name ~%qT",
11152 scope, TREE_OPERAND (expr, 0));
11153 expr = error_mark_node;
11156 expr = lookup_qualified_name (scope, complete_dtor_identifier,
11157 /*is_type_p=*/0, false);
11160 expr = lookup_qualified_name (scope, expr, /*is_type_p=*/0, false);
11161 if (TREE_CODE (TREE_CODE (expr) == TEMPLATE_DECL
11162 ? DECL_TEMPLATE_RESULT (expr) : expr) == TYPE_DECL)
11164 if (complain & tf_error)
11166 error ("dependent-name %qE is parsed as a non-type, but "
11167 "instantiation yields a type", qualified_id);
11168 inform (input_location, "say %<typename %E%> if a type is meant", qualified_id);
11170 return error_mark_node;
11176 check_accessibility_of_qualified_id (expr, /*object_type=*/NULL_TREE,
11178 /* Remember that there was a reference to this entity. */
11182 if (expr == error_mark_node || TREE_CODE (expr) == TREE_LIST)
11184 if (complain & tf_error)
11185 qualified_name_lookup_error (scope,
11186 TREE_OPERAND (qualified_id, 1),
11187 expr, input_location);
11188 return error_mark_node;
11192 expr = lookup_template_function (expr, template_args);
11194 if (expr == error_mark_node && complain & tf_error)
11195 qualified_name_lookup_error (scope, TREE_OPERAND (qualified_id, 1),
11196 expr, input_location);
11197 else if (TYPE_P (scope))
11199 expr = (adjust_result_of_qualified_name_lookup
11200 (expr, scope, current_class_type));
11201 expr = (finish_qualified_id_expr
11202 (scope, expr, done, address_p,
11203 QUALIFIED_NAME_IS_TEMPLATE (qualified_id),
11204 /*template_arg_p=*/false));
11207 /* Expressions do not generally have reference type. */
11208 if (TREE_CODE (expr) != SCOPE_REF
11209 /* However, if we're about to form a pointer-to-member, we just
11210 want the referenced member referenced. */
11211 && TREE_CODE (expr) != OFFSET_REF)
11212 expr = convert_from_reference (expr);
11217 /* Like tsubst, but deals with expressions. This function just replaces
11218 template parms; to finish processing the resultant expression, use
11222 tsubst_copy (tree t, tree args, tsubst_flags_t complain, tree in_decl)
11224 enum tree_code code;
11227 if (t == NULL_TREE || t == error_mark_node || args == NULL_TREE)
11230 code = TREE_CODE (t);
11235 r = retrieve_local_specialization (t);
11240 /* This can happen for a parameter name used later in a function
11241 declaration (such as in a late-specified return type). Just
11242 make a dummy decl, since it's only used for its type. */
11243 gcc_assert (cp_unevaluated_operand != 0);
11244 /* We copy T because want to tsubst the PARM_DECL only,
11245 not the following PARM_DECLs that are chained to T. */
11247 r = tsubst_decl (c, args, complain);
11248 /* Give it the template pattern as its context; its true context
11249 hasn't been instantiated yet and this is good enough for
11251 DECL_CONTEXT (r) = DECL_CONTEXT (t);
11254 if (TREE_CODE (r) == ARGUMENT_PACK_SELECT)
11255 r = ARGUMENT_PACK_SELECT_ARG (r);
11264 if (DECL_TEMPLATE_PARM_P (t))
11265 return tsubst_copy (DECL_INITIAL (t), args, complain, in_decl);
11266 /* There is no need to substitute into namespace-scope
11268 if (DECL_NAMESPACE_SCOPE_P (t))
11270 /* If ARGS is NULL, then T is known to be non-dependent. */
11271 if (args == NULL_TREE)
11272 return integral_constant_value (t);
11274 /* Unfortunately, we cannot just call lookup_name here.
11277 template <int I> int f() {
11279 struct S { void g() { E e = a; } };
11282 When we instantiate f<7>::S::g(), say, lookup_name is not
11283 clever enough to find f<7>::a. */
11285 = tsubst_aggr_type (TREE_TYPE (t), args, complain, in_decl,
11286 /*entering_scope=*/0);
11288 for (v = TYPE_VALUES (enum_type);
11290 v = TREE_CHAIN (v))
11291 if (TREE_PURPOSE (v) == DECL_NAME (t))
11292 return TREE_VALUE (v);
11294 /* We didn't find the name. That should never happen; if
11295 name-lookup found it during preliminary parsing, we
11296 should find it again here during instantiation. */
11297 gcc_unreachable ();
11302 if (DECL_CONTEXT (t))
11306 ctx = tsubst_aggr_type (DECL_CONTEXT (t), args, complain, in_decl,
11307 /*entering_scope=*/1);
11308 if (ctx != DECL_CONTEXT (t))
11310 tree r = lookup_field (ctx, DECL_NAME (t), 0, false);
11313 if (complain & tf_error)
11314 error ("using invalid field %qD", t);
11315 return error_mark_node;
11324 case FUNCTION_DECL:
11325 if ((DECL_LANG_SPECIFIC (t) && DECL_TEMPLATE_INFO (t))
11326 || local_variable_p (t))
11327 t = tsubst (t, args, complain, in_decl);
11332 /* An OVERLOAD will always be a non-dependent overload set; an
11333 overload set from function scope will just be represented with an
11334 IDENTIFIER_NODE, and from class scope with a BASELINK. */
11335 gcc_assert (!uses_template_parms (t));
11339 return tsubst_baselink (t, current_class_type, args, complain, in_decl);
11341 case TEMPLATE_DECL:
11342 if (DECL_TEMPLATE_TEMPLATE_PARM_P (t))
11343 return tsubst (TREE_TYPE (DECL_TEMPLATE_RESULT (t)),
11344 args, complain, in_decl);
11345 else if (DECL_FUNCTION_TEMPLATE_P (t) && DECL_MEMBER_TEMPLATE_P (t))
11346 return tsubst (t, args, complain, in_decl);
11347 else if (DECL_CLASS_SCOPE_P (t)
11348 && uses_template_parms (DECL_CONTEXT (t)))
11350 /* Template template argument like the following example need
11353 template <template <class> class TT> struct C {};
11354 template <class T> struct D {
11355 template <class U> struct E {};
11360 We are processing the template argument `E' in #1 for
11361 the template instantiation #2. Originally, `E' is a
11362 TEMPLATE_DECL with `D<T>' as its DECL_CONTEXT. Now we
11363 have to substitute this with one having context `D<int>'. */
11365 tree context = tsubst (DECL_CONTEXT (t), args, complain, in_decl);
11366 return lookup_field (context, DECL_NAME(t), 0, false);
11369 /* Ordinary template template argument. */
11373 case REINTERPRET_CAST_EXPR:
11374 case CONST_CAST_EXPR:
11375 case STATIC_CAST_EXPR:
11376 case DYNAMIC_CAST_EXPR:
11379 (code, tsubst (TREE_TYPE (t), args, complain, in_decl),
11380 tsubst_copy (TREE_OPERAND (t, 0), args, complain, in_decl));
11383 if (PACK_EXPANSION_P (TREE_OPERAND (t, 0)))
11389 ++cp_unevaluated_operand;
11390 ++c_inhibit_evaluation_warnings;
11391 /* We only want to compute the number of arguments. */
11392 expanded = tsubst_pack_expansion (TREE_OPERAND (t, 0), args,
11393 complain, in_decl);
11394 --cp_unevaluated_operand;
11395 --c_inhibit_evaluation_warnings;
11397 if (TREE_CODE (expanded) == TREE_VEC)
11398 len = TREE_VEC_LENGTH (expanded);
11400 if (expanded == error_mark_node)
11401 return error_mark_node;
11402 else if (PACK_EXPANSION_P (expanded)
11403 || (TREE_CODE (expanded) == TREE_VEC
11405 && PACK_EXPANSION_P (TREE_VEC_ELT (expanded, len-1))))
11407 if (TREE_CODE (expanded) == TREE_VEC)
11408 expanded = TREE_VEC_ELT (expanded, len - 1);
11410 if (TYPE_P (expanded))
11411 return cxx_sizeof_or_alignof_type (expanded, SIZEOF_EXPR,
11412 complain & tf_error);
11414 return cxx_sizeof_or_alignof_expr (expanded, SIZEOF_EXPR,
11415 complain & tf_error);
11418 return build_int_cst (size_type_node, len);
11424 case TRUTH_NOT_EXPR:
11427 case UNARY_PLUS_EXPR: /* Unary + */
11429 case AT_ENCODE_EXPR:
11433 case REALPART_EXPR:
11434 case IMAGPART_EXPR:
11436 (code, tsubst (TREE_TYPE (t), args, complain, in_decl),
11437 tsubst_copy (TREE_OPERAND (t, 0), args, complain, in_decl));
11439 case COMPONENT_REF:
11444 object = tsubst_copy (TREE_OPERAND (t, 0), args, complain, in_decl);
11445 name = TREE_OPERAND (t, 1);
11446 if (TREE_CODE (name) == BIT_NOT_EXPR)
11448 name = tsubst_copy (TREE_OPERAND (name, 0), args,
11449 complain, in_decl);
11450 name = build1 (BIT_NOT_EXPR, NULL_TREE, name);
11452 else if (TREE_CODE (name) == SCOPE_REF
11453 && TREE_CODE (TREE_OPERAND (name, 1)) == BIT_NOT_EXPR)
11455 tree base = tsubst_copy (TREE_OPERAND (name, 0), args,
11456 complain, in_decl);
11457 name = TREE_OPERAND (name, 1);
11458 name = tsubst_copy (TREE_OPERAND (name, 0), args,
11459 complain, in_decl);
11460 name = build1 (BIT_NOT_EXPR, NULL_TREE, name);
11461 name = build_qualified_name (/*type=*/NULL_TREE,
11463 /*template_p=*/false);
11465 else if (TREE_CODE (name) == BASELINK)
11466 name = tsubst_baselink (name,
11467 non_reference (TREE_TYPE (object)),
11471 name = tsubst_copy (name, args, complain, in_decl);
11472 return build_nt (COMPONENT_REF, object, name, NULL_TREE);
11478 case TRUNC_DIV_EXPR:
11479 case CEIL_DIV_EXPR:
11480 case FLOOR_DIV_EXPR:
11481 case ROUND_DIV_EXPR:
11482 case EXACT_DIV_EXPR:
11486 case TRUNC_MOD_EXPR:
11487 case FLOOR_MOD_EXPR:
11488 case TRUTH_ANDIF_EXPR:
11489 case TRUTH_ORIF_EXPR:
11490 case TRUTH_AND_EXPR:
11491 case TRUTH_OR_EXPR:
11504 case COMPOUND_EXPR:
11507 case PREDECREMENT_EXPR:
11508 case PREINCREMENT_EXPR:
11509 case POSTDECREMENT_EXPR:
11510 case POSTINCREMENT_EXPR:
11512 (code, tsubst_copy (TREE_OPERAND (t, 0), args, complain, in_decl),
11513 tsubst_copy (TREE_OPERAND (t, 1), args, complain, in_decl));
11516 return build_qualified_name (/*type=*/NULL_TREE,
11517 tsubst_copy (TREE_OPERAND (t, 0),
11518 args, complain, in_decl),
11519 tsubst_copy (TREE_OPERAND (t, 1),
11520 args, complain, in_decl),
11521 QUALIFIED_NAME_IS_TEMPLATE (t));
11526 tsubst_copy (TREE_OPERAND (t, 0), args, complain, in_decl),
11527 tsubst_copy (TREE_OPERAND (t, 1), args, complain, in_decl),
11528 NULL_TREE, NULL_TREE);
11532 int n = VL_EXP_OPERAND_LENGTH (t);
11533 tree result = build_vl_exp (CALL_EXPR, n);
11535 for (i = 0; i < n; i++)
11536 TREE_OPERAND (t, i) = tsubst_copy (TREE_OPERAND (t, i), args,
11537 complain, in_decl);
11543 case PSEUDO_DTOR_EXPR:
11546 (code, tsubst_copy (TREE_OPERAND (t, 0), args, complain, in_decl),
11547 tsubst_copy (TREE_OPERAND (t, 1), args, complain, in_decl),
11548 tsubst_copy (TREE_OPERAND (t, 2), args, complain, in_decl));
11549 TREE_NO_WARNING (r) = TREE_NO_WARNING (t);
11556 (code, tsubst_copy (TREE_OPERAND (t, 0), args, complain, in_decl),
11557 tsubst_copy (TREE_OPERAND (t, 1), args, complain, in_decl),
11558 tsubst_copy (TREE_OPERAND (t, 2), args, complain, in_decl));
11559 NEW_EXPR_USE_GLOBAL (r) = NEW_EXPR_USE_GLOBAL (t);
11566 (code, tsubst_copy (TREE_OPERAND (t, 0), args, complain, in_decl),
11567 tsubst_copy (TREE_OPERAND (t, 1), args, complain, in_decl));
11568 DELETE_EXPR_USE_GLOBAL (r) = DELETE_EXPR_USE_GLOBAL (t);
11569 DELETE_EXPR_USE_VEC (r) = DELETE_EXPR_USE_VEC (t);
11573 case TEMPLATE_ID_EXPR:
11575 /* Substituted template arguments */
11576 tree fn = TREE_OPERAND (t, 0);
11577 tree targs = TREE_OPERAND (t, 1);
11579 fn = tsubst_copy (fn, args, complain, in_decl);
11581 targs = tsubst_template_args (targs, args, complain, in_decl);
11583 return lookup_template_function (fn, targs);
11588 tree purpose, value, chain;
11590 if (t == void_list_node)
11593 purpose = TREE_PURPOSE (t);
11595 purpose = tsubst_copy (purpose, args, complain, in_decl);
11596 value = TREE_VALUE (t);
11598 value = tsubst_copy (value, args, complain, in_decl);
11599 chain = TREE_CHAIN (t);
11600 if (chain && chain != void_type_node)
11601 chain = tsubst_copy (chain, args, complain, in_decl);
11602 if (purpose == TREE_PURPOSE (t)
11603 && value == TREE_VALUE (t)
11604 && chain == TREE_CHAIN (t))
11606 return tree_cons (purpose, value, chain);
11611 case ENUMERAL_TYPE:
11613 case TEMPLATE_TYPE_PARM:
11614 case TEMPLATE_TEMPLATE_PARM:
11615 case BOUND_TEMPLATE_TEMPLATE_PARM:
11616 case TEMPLATE_PARM_INDEX:
11618 case REFERENCE_TYPE:
11620 case FUNCTION_TYPE:
11623 case TYPENAME_TYPE:
11624 case UNBOUND_CLASS_TEMPLATE:
11626 case DECLTYPE_TYPE:
11628 return tsubst (t, args, complain, in_decl);
11630 case IDENTIFIER_NODE:
11631 if (IDENTIFIER_TYPENAME_P (t))
11633 tree new_type = tsubst (TREE_TYPE (t), args, complain, in_decl);
11634 return mangle_conv_op_name_for_type (new_type);
11640 /* This is handled by tsubst_copy_and_build. */
11641 gcc_unreachable ();
11644 return build_x_va_arg (tsubst_copy (TREE_OPERAND (t, 0), args, complain,
11646 tsubst (TREE_TYPE (t), args, complain, in_decl));
11648 case CLEANUP_POINT_EXPR:
11649 /* We shouldn't have built any of these during initial template
11650 generation. Instead, they should be built during instantiation
11651 in response to the saved STMT_IS_FULL_EXPR_P setting. */
11652 gcc_unreachable ();
11656 (code, tsubst (TREE_TYPE (t), args, complain, in_decl),
11657 tsubst_copy (TREE_OPERAND (t, 0), args, complain, in_decl),
11658 tsubst_copy (TREE_OPERAND (t, 1), args, complain, in_decl));
11659 PTRMEM_OK_P (r) = PTRMEM_OK_P (t);
11660 mark_used (TREE_OPERAND (r, 1));
11663 case EXPR_PACK_EXPANSION:
11664 error ("invalid use of pack expansion expression");
11665 return error_mark_node;
11667 case NONTYPE_ARGUMENT_PACK:
11668 error ("use %<...%> to expand argument pack");
11669 return error_mark_node;
11676 /* Instantiate any typedefs in the type. */
11677 tree type = tsubst (TREE_TYPE (t), args, complain, in_decl);
11678 r = fold_convert (type, t);
11679 gcc_assert (TREE_CODE (r) == code);
11684 /* These can sometimes show up in a partial instantiation, but never
11685 involve template parms. */
11686 gcc_assert (!uses_template_parms (t));
11690 gcc_unreachable ();
11694 /* Like tsubst_copy, but specifically for OpenMP clauses. */
11697 tsubst_omp_clauses (tree clauses, tree args, tsubst_flags_t complain,
11700 tree new_clauses = NULL, nc, oc;
11702 for (oc = clauses; oc ; oc = OMP_CLAUSE_CHAIN (oc))
11704 nc = copy_node (oc);
11705 OMP_CLAUSE_CHAIN (nc) = new_clauses;
11708 switch (OMP_CLAUSE_CODE (nc))
11710 case OMP_CLAUSE_LASTPRIVATE:
11711 if (OMP_CLAUSE_LASTPRIVATE_STMT (oc))
11713 OMP_CLAUSE_LASTPRIVATE_STMT (nc) = push_stmt_list ();
11714 tsubst_expr (OMP_CLAUSE_LASTPRIVATE_STMT (oc), args, complain,
11715 in_decl, /*integral_constant_expression_p=*/false);
11716 OMP_CLAUSE_LASTPRIVATE_STMT (nc)
11717 = pop_stmt_list (OMP_CLAUSE_LASTPRIVATE_STMT (nc));
11720 case OMP_CLAUSE_PRIVATE:
11721 case OMP_CLAUSE_SHARED:
11722 case OMP_CLAUSE_FIRSTPRIVATE:
11723 case OMP_CLAUSE_REDUCTION:
11724 case OMP_CLAUSE_COPYIN:
11725 case OMP_CLAUSE_COPYPRIVATE:
11726 case OMP_CLAUSE_IF:
11727 case OMP_CLAUSE_NUM_THREADS:
11728 case OMP_CLAUSE_SCHEDULE:
11729 case OMP_CLAUSE_COLLAPSE:
11730 OMP_CLAUSE_OPERAND (nc, 0)
11731 = tsubst_expr (OMP_CLAUSE_OPERAND (oc, 0), args, complain,
11732 in_decl, /*integral_constant_expression_p=*/false);
11734 case OMP_CLAUSE_NOWAIT:
11735 case OMP_CLAUSE_ORDERED:
11736 case OMP_CLAUSE_DEFAULT:
11737 case OMP_CLAUSE_UNTIED:
11740 gcc_unreachable ();
11744 return finish_omp_clauses (nreverse (new_clauses));
11747 /* Like tsubst_copy_and_build, but unshare TREE_LIST nodes. */
11750 tsubst_copy_asm_operands (tree t, tree args, tsubst_flags_t complain,
11753 #define RECUR(t) tsubst_copy_asm_operands (t, args, complain, in_decl)
11755 tree purpose, value, chain;
11760 if (TREE_CODE (t) != TREE_LIST)
11761 return tsubst_copy_and_build (t, args, complain, in_decl,
11762 /*function_p=*/false,
11763 /*integral_constant_expression_p=*/false);
11765 if (t == void_list_node)
11768 purpose = TREE_PURPOSE (t);
11770 purpose = RECUR (purpose);
11771 value = TREE_VALUE (t);
11772 if (value && TREE_CODE (value) != LABEL_DECL)
11773 value = RECUR (value);
11774 chain = TREE_CHAIN (t);
11775 if (chain && chain != void_type_node)
11776 chain = RECUR (chain);
11777 return tree_cons (purpose, value, chain);
11781 /* Substitute one OMP_FOR iterator. */
11784 tsubst_omp_for_iterator (tree t, int i, tree declv, tree initv,
11785 tree condv, tree incrv, tree *clauses,
11786 tree args, tsubst_flags_t complain, tree in_decl,
11787 bool integral_constant_expression_p)
11789 #define RECUR(NODE) \
11790 tsubst_expr ((NODE), args, complain, in_decl, \
11791 integral_constant_expression_p)
11792 tree decl, init, cond, incr, auto_node;
11794 init = TREE_VEC_ELT (OMP_FOR_INIT (t), i);
11795 gcc_assert (TREE_CODE (init) == MODIFY_EXPR);
11796 decl = RECUR (TREE_OPERAND (init, 0));
11797 init = TREE_OPERAND (init, 1);
11798 auto_node = type_uses_auto (TREE_TYPE (decl));
11799 if (auto_node && init)
11801 tree init_expr = init;
11802 if (TREE_CODE (init_expr) == DECL_EXPR)
11803 init_expr = DECL_INITIAL (DECL_EXPR_DECL (init_expr));
11804 init_expr = RECUR (init_expr);
11806 = do_auto_deduction (TREE_TYPE (decl), init_expr, auto_node);
11808 gcc_assert (!type_dependent_expression_p (decl));
11810 if (!CLASS_TYPE_P (TREE_TYPE (decl)))
11812 cond = RECUR (TREE_VEC_ELT (OMP_FOR_COND (t), i));
11813 incr = TREE_VEC_ELT (OMP_FOR_INCR (t), i);
11814 if (TREE_CODE (incr) == MODIFY_EXPR)
11815 incr = build_x_modify_expr (RECUR (TREE_OPERAND (incr, 0)), NOP_EXPR,
11816 RECUR (TREE_OPERAND (incr, 1)),
11819 incr = RECUR (incr);
11820 TREE_VEC_ELT (declv, i) = decl;
11821 TREE_VEC_ELT (initv, i) = init;
11822 TREE_VEC_ELT (condv, i) = cond;
11823 TREE_VEC_ELT (incrv, i) = incr;
11827 if (init && TREE_CODE (init) != DECL_EXPR)
11830 for (c = *clauses; c ; c = OMP_CLAUSE_CHAIN (c))
11832 if ((OMP_CLAUSE_CODE (c) == OMP_CLAUSE_PRIVATE
11833 || OMP_CLAUSE_CODE (c) == OMP_CLAUSE_LASTPRIVATE)
11834 && OMP_CLAUSE_DECL (c) == decl)
11836 else if (OMP_CLAUSE_CODE (c) == OMP_CLAUSE_FIRSTPRIVATE
11837 && OMP_CLAUSE_DECL (c) == decl)
11838 error ("iteration variable %qD should not be firstprivate", decl);
11839 else if (OMP_CLAUSE_CODE (c) == OMP_CLAUSE_REDUCTION
11840 && OMP_CLAUSE_DECL (c) == decl)
11841 error ("iteration variable %qD should not be reduction", decl);
11845 c = build_omp_clause (input_location, OMP_CLAUSE_PRIVATE);
11846 OMP_CLAUSE_DECL (c) = decl;
11847 c = finish_omp_clauses (c);
11850 OMP_CLAUSE_CHAIN (c) = *clauses;
11855 cond = TREE_VEC_ELT (OMP_FOR_COND (t), i);
11856 if (COMPARISON_CLASS_P (cond))
11857 cond = build2 (TREE_CODE (cond), boolean_type_node,
11858 RECUR (TREE_OPERAND (cond, 0)),
11859 RECUR (TREE_OPERAND (cond, 1)));
11861 cond = RECUR (cond);
11862 incr = TREE_VEC_ELT (OMP_FOR_INCR (t), i);
11863 switch (TREE_CODE (incr))
11865 case PREINCREMENT_EXPR:
11866 case PREDECREMENT_EXPR:
11867 case POSTINCREMENT_EXPR:
11868 case POSTDECREMENT_EXPR:
11869 incr = build2 (TREE_CODE (incr), TREE_TYPE (decl),
11870 RECUR (TREE_OPERAND (incr, 0)), NULL_TREE);
11873 if (TREE_CODE (TREE_OPERAND (incr, 1)) == PLUS_EXPR
11874 || TREE_CODE (TREE_OPERAND (incr, 1)) == MINUS_EXPR)
11876 tree rhs = TREE_OPERAND (incr, 1);
11877 incr = build2 (MODIFY_EXPR, TREE_TYPE (decl),
11878 RECUR (TREE_OPERAND (incr, 0)),
11879 build2 (TREE_CODE (rhs), TREE_TYPE (decl),
11880 RECUR (TREE_OPERAND (rhs, 0)),
11881 RECUR (TREE_OPERAND (rhs, 1))));
11884 incr = RECUR (incr);
11887 if (TREE_CODE (TREE_OPERAND (incr, 1)) == PLUS_EXPR
11888 || TREE_CODE (TREE_OPERAND (incr, 1)) == MINUS_EXPR)
11890 tree lhs = RECUR (TREE_OPERAND (incr, 0));
11891 incr = build2 (MODIFY_EXPR, TREE_TYPE (decl), lhs,
11892 build2 (TREE_CODE (TREE_OPERAND (incr, 1)),
11893 TREE_TYPE (decl), lhs,
11894 RECUR (TREE_OPERAND (incr, 2))));
11896 else if (TREE_CODE (TREE_OPERAND (incr, 1)) == NOP_EXPR
11897 && (TREE_CODE (TREE_OPERAND (incr, 2)) == PLUS_EXPR
11898 || (TREE_CODE (TREE_OPERAND (incr, 2)) == MINUS_EXPR)))
11900 tree rhs = TREE_OPERAND (incr, 2);
11901 incr = build2 (MODIFY_EXPR, TREE_TYPE (decl),
11902 RECUR (TREE_OPERAND (incr, 0)),
11903 build2 (TREE_CODE (rhs), TREE_TYPE (decl),
11904 RECUR (TREE_OPERAND (rhs, 0)),
11905 RECUR (TREE_OPERAND (rhs, 1))));
11908 incr = RECUR (incr);
11911 incr = RECUR (incr);
11915 TREE_VEC_ELT (declv, i) = decl;
11916 TREE_VEC_ELT (initv, i) = init;
11917 TREE_VEC_ELT (condv, i) = cond;
11918 TREE_VEC_ELT (incrv, i) = incr;
11922 /* Like tsubst_copy for expressions, etc. but also does semantic
11926 tsubst_expr (tree t, tree args, tsubst_flags_t complain, tree in_decl,
11927 bool integral_constant_expression_p)
11929 #define RECUR(NODE) \
11930 tsubst_expr ((NODE), args, complain, in_decl, \
11931 integral_constant_expression_p)
11935 if (t == NULL_TREE || t == error_mark_node)
11938 if (EXPR_HAS_LOCATION (t))
11939 input_location = EXPR_LOCATION (t);
11940 if (STATEMENT_CODE_P (TREE_CODE (t)))
11941 current_stmt_tree ()->stmts_are_full_exprs_p = STMT_IS_FULL_EXPR_P (t);
11943 switch (TREE_CODE (t))
11945 case STATEMENT_LIST:
11947 tree_stmt_iterator i;
11948 for (i = tsi_start (t); !tsi_end_p (i); tsi_next (&i))
11949 RECUR (tsi_stmt (i));
11953 case CTOR_INITIALIZER:
11954 finish_mem_initializers (tsubst_initializer_list
11955 (TREE_OPERAND (t, 0), args));
11959 finish_return_stmt (RECUR (TREE_OPERAND (t, 0)));
11963 tmp = RECUR (EXPR_STMT_EXPR (t));
11964 if (EXPR_STMT_STMT_EXPR_RESULT (t))
11965 finish_stmt_expr_expr (tmp, cur_stmt_expr);
11967 finish_expr_stmt (tmp);
11971 do_using_directive (USING_STMT_NAMESPACE (t));
11976 tree decl, pattern_decl;
11979 pattern_decl = decl = DECL_EXPR_DECL (t);
11980 if (TREE_CODE (decl) == LABEL_DECL)
11981 finish_label_decl (DECL_NAME (decl));
11982 else if (TREE_CODE (decl) == USING_DECL)
11984 tree scope = USING_DECL_SCOPE (decl);
11985 tree name = DECL_NAME (decl);
11988 scope = tsubst (scope, args, complain, in_decl);
11989 decl = lookup_qualified_name (scope, name,
11990 /*is_type_p=*/false,
11991 /*complain=*/false);
11992 if (decl == error_mark_node || TREE_CODE (decl) == TREE_LIST)
11993 qualified_name_lookup_error (scope, name, decl, input_location);
11995 do_local_using_decl (decl, scope, name);
11999 init = DECL_INITIAL (decl);
12000 decl = tsubst (decl, args, complain, in_decl);
12001 if (decl != error_mark_node)
12003 /* By marking the declaration as instantiated, we avoid
12004 trying to instantiate it. Since instantiate_decl can't
12005 handle local variables, and since we've already done
12006 all that needs to be done, that's the right thing to
12008 if (TREE_CODE (decl) == VAR_DECL)
12009 DECL_TEMPLATE_INSTANTIATED (decl) = 1;
12010 if (TREE_CODE (decl) == VAR_DECL
12011 && ANON_AGGR_TYPE_P (TREE_TYPE (decl)))
12012 /* Anonymous aggregates are a special case. */
12013 finish_anon_union (decl);
12016 int const_init = false;
12017 maybe_push_decl (decl);
12018 if (TREE_CODE (decl) == VAR_DECL
12019 && DECL_PRETTY_FUNCTION_P (decl))
12021 /* For __PRETTY_FUNCTION__ we have to adjust the
12023 const char *const name
12024 = cxx_printable_name (current_function_decl, 2);
12025 init = cp_fname_init (name, &TREE_TYPE (decl));
12029 tree t = RECUR (init);
12033 /* If we had an initializer but it
12034 instantiated to nothing,
12035 value-initialize the object. This will
12036 only occur when the initializer was a
12037 pack expansion where the parameter packs
12038 used in that expansion were of length
12040 init = build_value_init (TREE_TYPE (decl),
12042 if (TREE_CODE (init) == AGGR_INIT_EXPR)
12043 init = get_target_expr (init);
12049 if (TREE_CODE (decl) == VAR_DECL)
12050 const_init = (DECL_INITIALIZED_BY_CONSTANT_EXPRESSION_P
12052 cp_finish_decl (decl, init, const_init, NULL_TREE, 0);
12057 /* A DECL_EXPR can also be used as an expression, in the condition
12058 clause of an if/for/while construct. */
12063 stmt = begin_for_stmt (NULL_TREE, NULL_TREE);
12064 RECUR (FOR_INIT_STMT (t));
12065 finish_for_init_stmt (stmt);
12066 tmp = RECUR (FOR_COND (t));
12067 finish_for_cond (tmp, stmt);
12068 tmp = RECUR (FOR_EXPR (t));
12069 finish_for_expr (tmp, stmt);
12070 RECUR (FOR_BODY (t));
12071 finish_for_stmt (stmt);
12074 case RANGE_FOR_STMT:
12077 stmt = begin_for_stmt (NULL_TREE, NULL_TREE);
12078 decl = RANGE_FOR_DECL (t);
12079 decl = tsubst (decl, args, complain, in_decl);
12080 maybe_push_decl (decl);
12081 expr = RECUR (RANGE_FOR_EXPR (t));
12082 stmt = cp_convert_range_for (stmt, decl, expr);
12083 RECUR (RANGE_FOR_BODY (t));
12084 finish_for_stmt (stmt);
12089 stmt = begin_while_stmt ();
12090 tmp = RECUR (WHILE_COND (t));
12091 finish_while_stmt_cond (tmp, stmt);
12092 RECUR (WHILE_BODY (t));
12093 finish_while_stmt (stmt);
12097 stmt = begin_do_stmt ();
12098 RECUR (DO_BODY (t));
12099 finish_do_body (stmt);
12100 tmp = RECUR (DO_COND (t));
12101 finish_do_stmt (tmp, stmt);
12105 stmt = begin_if_stmt ();
12106 tmp = RECUR (IF_COND (t));
12107 finish_if_stmt_cond (tmp, stmt);
12108 RECUR (THEN_CLAUSE (t));
12109 finish_then_clause (stmt);
12111 if (ELSE_CLAUSE (t))
12113 begin_else_clause (stmt);
12114 RECUR (ELSE_CLAUSE (t));
12115 finish_else_clause (stmt);
12118 finish_if_stmt (stmt);
12122 if (BIND_EXPR_BODY_BLOCK (t))
12123 stmt = begin_function_body ();
12125 stmt = begin_compound_stmt (BIND_EXPR_TRY_BLOCK (t)
12126 ? BCS_TRY_BLOCK : 0);
12128 RECUR (BIND_EXPR_BODY (t));
12130 if (BIND_EXPR_BODY_BLOCK (t))
12131 finish_function_body (stmt);
12133 finish_compound_stmt (stmt);
12137 finish_break_stmt ();
12140 case CONTINUE_STMT:
12141 finish_continue_stmt ();
12145 stmt = begin_switch_stmt ();
12146 tmp = RECUR (SWITCH_STMT_COND (t));
12147 finish_switch_cond (tmp, stmt);
12148 RECUR (SWITCH_STMT_BODY (t));
12149 finish_switch_stmt (stmt);
12152 case CASE_LABEL_EXPR:
12153 finish_case_label (EXPR_LOCATION (t),
12154 RECUR (CASE_LOW (t)),
12155 RECUR (CASE_HIGH (t)));
12160 tree decl = LABEL_EXPR_LABEL (t);
12163 label = finish_label_stmt (DECL_NAME (decl));
12164 if (DECL_ATTRIBUTES (decl) != NULL_TREE)
12165 cplus_decl_attributes (&label, DECL_ATTRIBUTES (decl), 0);
12170 tmp = GOTO_DESTINATION (t);
12171 if (TREE_CODE (tmp) != LABEL_DECL)
12172 /* Computed goto's must be tsubst'd into. On the other hand,
12173 non-computed gotos must not be; the identifier in question
12174 will have no binding. */
12177 tmp = DECL_NAME (tmp);
12178 finish_goto_stmt (tmp);
12182 tmp = finish_asm_stmt
12183 (ASM_VOLATILE_P (t),
12184 RECUR (ASM_STRING (t)),
12185 tsubst_copy_asm_operands (ASM_OUTPUTS (t), args, complain, in_decl),
12186 tsubst_copy_asm_operands (ASM_INPUTS (t), args, complain, in_decl),
12187 tsubst_copy_asm_operands (ASM_CLOBBERS (t), args, complain, in_decl),
12188 tsubst_copy_asm_operands (ASM_LABELS (t), args, complain, in_decl));
12190 tree asm_expr = tmp;
12191 if (TREE_CODE (asm_expr) == CLEANUP_POINT_EXPR)
12192 asm_expr = TREE_OPERAND (asm_expr, 0);
12193 ASM_INPUT_P (asm_expr) = ASM_INPUT_P (t);
12200 stmt = begin_try_block ();
12201 RECUR (TRY_STMTS (t));
12202 finish_cleanup_try_block (stmt);
12203 finish_cleanup (RECUR (TRY_HANDLERS (t)), stmt);
12207 tree compound_stmt = NULL_TREE;
12209 if (FN_TRY_BLOCK_P (t))
12210 stmt = begin_function_try_block (&compound_stmt);
12212 stmt = begin_try_block ();
12214 RECUR (TRY_STMTS (t));
12216 if (FN_TRY_BLOCK_P (t))
12217 finish_function_try_block (stmt);
12219 finish_try_block (stmt);
12221 RECUR (TRY_HANDLERS (t));
12222 if (FN_TRY_BLOCK_P (t))
12223 finish_function_handler_sequence (stmt, compound_stmt);
12225 finish_handler_sequence (stmt);
12231 tree decl = HANDLER_PARMS (t);
12235 decl = tsubst (decl, args, complain, in_decl);
12236 /* Prevent instantiate_decl from trying to instantiate
12237 this variable. We've already done all that needs to be
12239 if (decl != error_mark_node)
12240 DECL_TEMPLATE_INSTANTIATED (decl) = 1;
12242 stmt = begin_handler ();
12243 finish_handler_parms (decl, stmt);
12244 RECUR (HANDLER_BODY (t));
12245 finish_handler (stmt);
12250 tsubst (TREE_TYPE (t), args, complain, NULL_TREE);
12253 case STATIC_ASSERT:
12256 tsubst_expr (STATIC_ASSERT_CONDITION (t),
12259 /*integral_constant_expression_p=*/true);
12260 finish_static_assert (condition,
12261 STATIC_ASSERT_MESSAGE (t),
12262 STATIC_ASSERT_SOURCE_LOCATION (t),
12263 /*member_p=*/false);
12268 tmp = tsubst_omp_clauses (OMP_PARALLEL_CLAUSES (t),
12269 args, complain, in_decl);
12270 stmt = begin_omp_parallel ();
12271 RECUR (OMP_PARALLEL_BODY (t));
12272 OMP_PARALLEL_COMBINED (finish_omp_parallel (tmp, stmt))
12273 = OMP_PARALLEL_COMBINED (t);
12277 tmp = tsubst_omp_clauses (OMP_TASK_CLAUSES (t),
12278 args, complain, in_decl);
12279 stmt = begin_omp_task ();
12280 RECUR (OMP_TASK_BODY (t));
12281 finish_omp_task (tmp, stmt);
12286 tree clauses, body, pre_body;
12287 tree declv, initv, condv, incrv;
12290 clauses = tsubst_omp_clauses (OMP_FOR_CLAUSES (t),
12291 args, complain, in_decl);
12292 declv = make_tree_vec (TREE_VEC_LENGTH (OMP_FOR_INIT (t)));
12293 initv = make_tree_vec (TREE_VEC_LENGTH (OMP_FOR_INIT (t)));
12294 condv = make_tree_vec (TREE_VEC_LENGTH (OMP_FOR_INIT (t)));
12295 incrv = make_tree_vec (TREE_VEC_LENGTH (OMP_FOR_INIT (t)));
12297 for (i = 0; i < TREE_VEC_LENGTH (OMP_FOR_INIT (t)); i++)
12298 tsubst_omp_for_iterator (t, i, declv, initv, condv, incrv,
12299 &clauses, args, complain, in_decl,
12300 integral_constant_expression_p);
12302 stmt = begin_omp_structured_block ();
12304 for (i = 0; i < TREE_VEC_LENGTH (initv); i++)
12305 if (TREE_VEC_ELT (initv, i) == NULL
12306 || TREE_CODE (TREE_VEC_ELT (initv, i)) != DECL_EXPR)
12307 TREE_VEC_ELT (initv, i) = RECUR (TREE_VEC_ELT (initv, i));
12308 else if (CLASS_TYPE_P (TREE_TYPE (TREE_VEC_ELT (initv, i))))
12310 tree init = RECUR (TREE_VEC_ELT (initv, i));
12311 gcc_assert (init == TREE_VEC_ELT (declv, i));
12312 TREE_VEC_ELT (initv, i) = NULL_TREE;
12316 tree decl_expr = TREE_VEC_ELT (initv, i);
12317 tree init = DECL_INITIAL (DECL_EXPR_DECL (decl_expr));
12318 gcc_assert (init != NULL);
12319 TREE_VEC_ELT (initv, i) = RECUR (init);
12320 DECL_INITIAL (DECL_EXPR_DECL (decl_expr)) = NULL;
12322 DECL_INITIAL (DECL_EXPR_DECL (decl_expr)) = init;
12325 pre_body = push_stmt_list ();
12326 RECUR (OMP_FOR_PRE_BODY (t));
12327 pre_body = pop_stmt_list (pre_body);
12329 body = push_stmt_list ();
12330 RECUR (OMP_FOR_BODY (t));
12331 body = pop_stmt_list (body);
12333 t = finish_omp_for (EXPR_LOCATION (t), declv, initv, condv, incrv,
12334 body, pre_body, clauses);
12336 add_stmt (finish_omp_structured_block (stmt));
12342 tmp = tsubst_omp_clauses (OMP_CLAUSES (t), args, complain, in_decl);
12343 stmt = push_stmt_list ();
12344 RECUR (OMP_BODY (t));
12345 stmt = pop_stmt_list (stmt);
12348 OMP_BODY (t) = stmt;
12349 OMP_CLAUSES (t) = tmp;
12357 stmt = push_stmt_list ();
12358 RECUR (OMP_BODY (t));
12359 stmt = pop_stmt_list (stmt);
12362 OMP_BODY (t) = stmt;
12367 gcc_assert (OMP_ATOMIC_DEPENDENT_P (t));
12369 tree op1 = TREE_OPERAND (t, 1);
12370 tree lhs = RECUR (TREE_OPERAND (op1, 0));
12371 tree rhs = RECUR (TREE_OPERAND (op1, 1));
12372 finish_omp_atomic (TREE_CODE (op1), lhs, rhs);
12376 case EXPR_PACK_EXPANSION:
12377 error ("invalid use of pack expansion expression");
12378 return error_mark_node;
12380 case NONTYPE_ARGUMENT_PACK:
12381 error ("use %<...%> to expand argument pack");
12382 return error_mark_node;
12385 gcc_assert (!STATEMENT_CODE_P (TREE_CODE (t)));
12387 return tsubst_copy_and_build (t, args, complain, in_decl,
12388 /*function_p=*/false,
12389 integral_constant_expression_p);
12396 /* T is a postfix-expression that is not being used in a function
12397 call. Return the substituted version of T. */
12400 tsubst_non_call_postfix_expression (tree t, tree args,
12401 tsubst_flags_t complain,
12404 if (TREE_CODE (t) == SCOPE_REF)
12405 t = tsubst_qualified_id (t, args, complain, in_decl,
12406 /*done=*/false, /*address_p=*/false);
12408 t = tsubst_copy_and_build (t, args, complain, in_decl,
12409 /*function_p=*/false,
12410 /*integral_constant_expression_p=*/false);
12415 /* Like tsubst but deals with expressions and performs semantic
12416 analysis. FUNCTION_P is true if T is the "F" in "F (ARGS)". */
12419 tsubst_copy_and_build (tree t,
12421 tsubst_flags_t complain,
12424 bool integral_constant_expression_p)
12426 #define RECUR(NODE) \
12427 tsubst_copy_and_build (NODE, args, complain, in_decl, \
12428 /*function_p=*/false, \
12429 integral_constant_expression_p)
12433 if (t == NULL_TREE || t == error_mark_node)
12436 switch (TREE_CODE (t))
12440 /* Fall through. */
12441 case IDENTIFIER_NODE:
12445 bool non_integral_constant_expression_p;
12446 const char *error_msg;
12448 if (IDENTIFIER_TYPENAME_P (t))
12450 tree new_type = tsubst (TREE_TYPE (t), args, complain, in_decl);
12451 t = mangle_conv_op_name_for_type (new_type);
12454 /* Look up the name. */
12455 decl = lookup_name (t);
12457 /* By convention, expressions use ERROR_MARK_NODE to indicate
12458 failure, not NULL_TREE. */
12459 if (decl == NULL_TREE)
12460 decl = error_mark_node;
12462 decl = finish_id_expression (t, decl, NULL_TREE,
12464 integral_constant_expression_p,
12465 /*allow_non_integral_constant_expression_p=*/false,
12466 &non_integral_constant_expression_p,
12467 /*template_p=*/false,
12469 /*address_p=*/false,
12470 /*template_arg_p=*/false,
12475 if (!function_p && TREE_CODE (decl) == IDENTIFIER_NODE)
12476 decl = unqualified_name_lookup_error (decl);
12480 case TEMPLATE_ID_EXPR:
12483 tree templ = RECUR (TREE_OPERAND (t, 0));
12484 tree targs = TREE_OPERAND (t, 1);
12487 targs = tsubst_template_args (targs, args, complain, in_decl);
12489 if (TREE_CODE (templ) == COMPONENT_REF)
12491 object = TREE_OPERAND (templ, 0);
12492 templ = TREE_OPERAND (templ, 1);
12495 object = NULL_TREE;
12496 templ = lookup_template_function (templ, targs);
12499 return build3 (COMPONENT_REF, TREE_TYPE (templ),
12500 object, templ, NULL_TREE);
12502 return baselink_for_fns (templ);
12507 tree r = RECUR (TREE_OPERAND (t, 0));
12509 if (REFERENCE_REF_P (t))
12511 /* A type conversion to reference type will be enclosed in
12512 such an indirect ref, but the substitution of the cast
12513 will have also added such an indirect ref. */
12514 if (TREE_CODE (TREE_TYPE (r)) == REFERENCE_TYPE)
12515 r = convert_from_reference (r);
12518 r = build_x_indirect_ref (r, RO_UNARY_STAR, complain);
12524 (tsubst (TREE_TYPE (t), args, complain, in_decl),
12525 RECUR (TREE_OPERAND (t, 0)));
12528 case REINTERPRET_CAST_EXPR:
12529 case CONST_CAST_EXPR:
12530 case DYNAMIC_CAST_EXPR:
12531 case STATIC_CAST_EXPR:
12536 type = tsubst (TREE_TYPE (t), args, complain, in_decl);
12537 if (integral_constant_expression_p
12538 && !cast_valid_in_integral_constant_expression_p (type))
12540 if (complain & tf_error)
12541 error ("a cast to a type other than an integral or "
12542 "enumeration type cannot appear in a constant-expression");
12543 return error_mark_node;
12546 op = RECUR (TREE_OPERAND (t, 0));
12548 switch (TREE_CODE (t))
12551 return build_functional_cast (type, op, complain);
12552 case REINTERPRET_CAST_EXPR:
12553 return build_reinterpret_cast (type, op, complain);
12554 case CONST_CAST_EXPR:
12555 return build_const_cast (type, op, complain);
12556 case DYNAMIC_CAST_EXPR:
12557 return build_dynamic_cast (type, op, complain);
12558 case STATIC_CAST_EXPR:
12559 return build_static_cast (type, op, complain);
12561 gcc_unreachable ();
12565 case POSTDECREMENT_EXPR:
12566 case POSTINCREMENT_EXPR:
12567 op1 = tsubst_non_call_postfix_expression (TREE_OPERAND (t, 0),
12568 args, complain, in_decl);
12569 return build_x_unary_op (TREE_CODE (t), op1, complain);
12571 case PREDECREMENT_EXPR:
12572 case PREINCREMENT_EXPR:
12576 case TRUTH_NOT_EXPR:
12577 case UNARY_PLUS_EXPR: /* Unary + */
12578 case REALPART_EXPR:
12579 case IMAGPART_EXPR:
12580 return build_x_unary_op (TREE_CODE (t), RECUR (TREE_OPERAND (t, 0)),
12584 op1 = TREE_OPERAND (t, 0);
12585 if (TREE_CODE (op1) == LABEL_DECL)
12586 return finish_label_address_expr (DECL_NAME (op1),
12587 EXPR_LOCATION (op1));
12588 if (TREE_CODE (op1) == SCOPE_REF)
12589 op1 = tsubst_qualified_id (op1, args, complain, in_decl,
12590 /*done=*/true, /*address_p=*/true);
12592 op1 = tsubst_non_call_postfix_expression (op1, args, complain,
12594 return build_x_unary_op (ADDR_EXPR, op1, complain);
12599 case TRUNC_DIV_EXPR:
12600 case CEIL_DIV_EXPR:
12601 case FLOOR_DIV_EXPR:
12602 case ROUND_DIV_EXPR:
12603 case EXACT_DIV_EXPR:
12607 case TRUNC_MOD_EXPR:
12608 case FLOOR_MOD_EXPR:
12609 case TRUTH_ANDIF_EXPR:
12610 case TRUTH_ORIF_EXPR:
12611 case TRUTH_AND_EXPR:
12612 case TRUTH_OR_EXPR:
12627 return build_x_binary_op
12629 RECUR (TREE_OPERAND (t, 0)),
12630 (TREE_NO_WARNING (TREE_OPERAND (t, 0))
12632 : TREE_CODE (TREE_OPERAND (t, 0))),
12633 RECUR (TREE_OPERAND (t, 1)),
12634 (TREE_NO_WARNING (TREE_OPERAND (t, 1))
12636 : TREE_CODE (TREE_OPERAND (t, 1))),
12637 /*overloaded_p=*/NULL,
12641 return tsubst_qualified_id (t, args, complain, in_decl, /*done=*/true,
12642 /*address_p=*/false);
12644 op1 = tsubst_non_call_postfix_expression (TREE_OPERAND (t, 0),
12645 args, complain, in_decl);
12646 return build_x_array_ref (op1, RECUR (TREE_OPERAND (t, 1)), complain);
12649 if (PACK_EXPANSION_P (TREE_OPERAND (t, 0)))
12650 return tsubst_copy (t, args, complain, in_decl);
12654 op1 = TREE_OPERAND (t, 0);
12657 /* When there are no ARGS, we are trying to evaluate a
12658 non-dependent expression from the parser. Trying to do
12659 the substitutions may not work. */
12661 op1 = TREE_TYPE (op1);
12665 ++cp_unevaluated_operand;
12666 ++c_inhibit_evaluation_warnings;
12667 op1 = tsubst_copy_and_build (op1, args, complain, in_decl,
12668 /*function_p=*/false,
12669 /*integral_constant_expression_p=*/false);
12670 --cp_unevaluated_operand;
12671 --c_inhibit_evaluation_warnings;
12674 return cxx_sizeof_or_alignof_type (op1, TREE_CODE (t),
12675 complain & tf_error);
12677 return cxx_sizeof_or_alignof_expr (op1, TREE_CODE (t),
12678 complain & tf_error);
12680 case AT_ENCODE_EXPR:
12682 op1 = TREE_OPERAND (t, 0);
12683 ++cp_unevaluated_operand;
12684 ++c_inhibit_evaluation_warnings;
12685 op1 = tsubst_copy_and_build (op1, args, complain, in_decl,
12686 /*function_p=*/false,
12687 /*integral_constant_expression_p=*/false);
12688 --cp_unevaluated_operand;
12689 --c_inhibit_evaluation_warnings;
12690 return objc_build_encode_expr (op1);
12693 case NOEXCEPT_EXPR:
12694 op1 = TREE_OPERAND (t, 0);
12695 ++cp_unevaluated_operand;
12696 ++c_inhibit_evaluation_warnings;
12697 op1 = tsubst_copy_and_build (op1, args, complain, in_decl,
12698 /*function_p=*/false,
12699 /*integral_constant_expression_p=*/false);
12700 --cp_unevaluated_operand;
12701 --c_inhibit_evaluation_warnings;
12702 return finish_noexcept_expr (op1, complain);
12706 tree r = build_x_modify_expr
12707 (RECUR (TREE_OPERAND (t, 0)),
12708 TREE_CODE (TREE_OPERAND (t, 1)),
12709 RECUR (TREE_OPERAND (t, 2)),
12711 /* TREE_NO_WARNING must be set if either the expression was
12712 parenthesized or it uses an operator such as >>= rather
12713 than plain assignment. In the former case, it was already
12714 set and must be copied. In the latter case,
12715 build_x_modify_expr sets it and it must not be reset
12717 if (TREE_NO_WARNING (t))
12718 TREE_NO_WARNING (r) = TREE_NO_WARNING (t);
12723 op1 = tsubst_non_call_postfix_expression (TREE_OPERAND (t, 0),
12724 args, complain, in_decl);
12725 /* Remember that there was a reference to this entity. */
12728 return build_x_arrow (op1);
12732 tree placement = RECUR (TREE_OPERAND (t, 0));
12733 tree init = RECUR (TREE_OPERAND (t, 3));
12734 VEC(tree,gc) *placement_vec;
12735 VEC(tree,gc) *init_vec;
12738 if (placement == NULL_TREE)
12739 placement_vec = NULL;
12742 placement_vec = make_tree_vector ();
12743 for (; placement != NULL_TREE; placement = TREE_CHAIN (placement))
12744 VEC_safe_push (tree, gc, placement_vec, TREE_VALUE (placement));
12747 /* If there was an initializer in the original tree, but it
12748 instantiated to an empty list, then we should pass a
12749 non-NULL empty vector to tell build_new that it was an
12750 empty initializer() rather than no initializer. This can
12751 only happen when the initializer is a pack expansion whose
12752 parameter packs are of length zero. */
12753 if (init == NULL_TREE && TREE_OPERAND (t, 3) == NULL_TREE)
12757 init_vec = make_tree_vector ();
12758 if (init == void_zero_node)
12759 gcc_assert (init_vec != NULL);
12762 for (; init != NULL_TREE; init = TREE_CHAIN (init))
12763 VEC_safe_push (tree, gc, init_vec, TREE_VALUE (init));
12767 ret = build_new (&placement_vec,
12768 tsubst (TREE_OPERAND (t, 1), args, complain, in_decl),
12769 RECUR (TREE_OPERAND (t, 2)),
12771 NEW_EXPR_USE_GLOBAL (t),
12774 if (placement_vec != NULL)
12775 release_tree_vector (placement_vec);
12776 if (init_vec != NULL)
12777 release_tree_vector (init_vec);
12783 return delete_sanity
12784 (RECUR (TREE_OPERAND (t, 0)),
12785 RECUR (TREE_OPERAND (t, 1)),
12786 DELETE_EXPR_USE_VEC (t),
12787 DELETE_EXPR_USE_GLOBAL (t));
12789 case COMPOUND_EXPR:
12790 return build_x_compound_expr (RECUR (TREE_OPERAND (t, 0)),
12791 RECUR (TREE_OPERAND (t, 1)),
12797 VEC(tree,gc) *call_args;
12798 unsigned int nargs, i;
12803 function = CALL_EXPR_FN (t);
12804 /* When we parsed the expression, we determined whether or
12805 not Koenig lookup should be performed. */
12806 koenig_p = KOENIG_LOOKUP_P (t);
12807 if (TREE_CODE (function) == SCOPE_REF)
12809 qualified_p = true;
12810 function = tsubst_qualified_id (function, args, complain, in_decl,
12812 /*address_p=*/false);
12816 if (TREE_CODE (function) == COMPONENT_REF)
12818 tree op = TREE_OPERAND (function, 1);
12820 qualified_p = (TREE_CODE (op) == SCOPE_REF
12821 || (BASELINK_P (op)
12822 && BASELINK_QUALIFIED_P (op)));
12825 qualified_p = false;
12827 function = tsubst_copy_and_build (function, args, complain,
12830 integral_constant_expression_p);
12832 if (BASELINK_P (function))
12833 qualified_p = true;
12836 nargs = call_expr_nargs (t);
12837 call_args = make_tree_vector ();
12838 for (i = 0; i < nargs; ++i)
12840 tree arg = CALL_EXPR_ARG (t, i);
12842 if (!PACK_EXPANSION_P (arg))
12843 VEC_safe_push (tree, gc, call_args,
12844 RECUR (CALL_EXPR_ARG (t, i)));
12847 /* Expand the pack expansion and push each entry onto
12849 arg = tsubst_pack_expansion (arg, args, complain, in_decl);
12850 if (TREE_CODE (arg) == TREE_VEC)
12852 unsigned int len, j;
12854 len = TREE_VEC_LENGTH (arg);
12855 for (j = 0; j < len; ++j)
12857 tree value = TREE_VEC_ELT (arg, j);
12858 if (value != NULL_TREE)
12859 value = convert_from_reference (value);
12860 VEC_safe_push (tree, gc, call_args, value);
12865 /* A partial substitution. Add one entry. */
12866 VEC_safe_push (tree, gc, call_args, arg);
12871 /* We do not perform argument-dependent lookup if normal
12872 lookup finds a non-function, in accordance with the
12873 expected resolution of DR 218. */
12875 && ((is_overloaded_fn (function)
12876 /* If lookup found a member function, the Koenig lookup is
12877 not appropriate, even if an unqualified-name was used
12878 to denote the function. */
12879 && !DECL_FUNCTION_MEMBER_P (get_first_fn (function)))
12880 || TREE_CODE (function) == IDENTIFIER_NODE)
12881 /* Only do this when substitution turns a dependent call
12882 into a non-dependent call. */
12883 && type_dependent_expression_p_push (t)
12884 && !any_type_dependent_arguments_p (call_args))
12885 function = perform_koenig_lookup (function, call_args, false);
12887 if (TREE_CODE (function) == IDENTIFIER_NODE)
12889 unqualified_name_lookup_error (function);
12890 release_tree_vector (call_args);
12891 return error_mark_node;
12894 /* Remember that there was a reference to this entity. */
12895 if (DECL_P (function))
12896 mark_used (function);
12898 if (TREE_CODE (function) == OFFSET_REF)
12899 ret = build_offset_ref_call_from_tree (function, &call_args);
12900 else if (TREE_CODE (function) == COMPONENT_REF)
12902 tree instance = TREE_OPERAND (function, 0);
12903 tree fn = TREE_OPERAND (function, 1);
12905 if (processing_template_decl
12906 && (type_dependent_expression_p (instance)
12907 || (!BASELINK_P (fn)
12908 && TREE_CODE (fn) != FIELD_DECL)
12909 || type_dependent_expression_p (fn)
12910 || any_type_dependent_arguments_p (call_args)))
12911 ret = build_nt_call_vec (function, call_args);
12912 else if (!BASELINK_P (fn))
12913 ret = finish_call_expr (function, &call_args,
12914 /*disallow_virtual=*/false,
12915 /*koenig_p=*/false,
12918 ret = (build_new_method_call
12920 &call_args, NULL_TREE,
12921 qualified_p ? LOOKUP_NONVIRTUAL : LOOKUP_NORMAL,
12926 ret = finish_call_expr (function, &call_args,
12927 /*disallow_virtual=*/qualified_p,
12931 release_tree_vector (call_args);
12937 return build_x_conditional_expr
12938 (RECUR (TREE_OPERAND (t, 0)),
12939 RECUR (TREE_OPERAND (t, 1)),
12940 RECUR (TREE_OPERAND (t, 2)),
12943 case PSEUDO_DTOR_EXPR:
12944 return finish_pseudo_destructor_expr
12945 (RECUR (TREE_OPERAND (t, 0)),
12946 RECUR (TREE_OPERAND (t, 1)),
12947 RECUR (TREE_OPERAND (t, 2)));
12951 tree purpose, value, chain;
12953 if (t == void_list_node)
12956 if ((TREE_PURPOSE (t) && PACK_EXPANSION_P (TREE_PURPOSE (t)))
12957 || (TREE_VALUE (t) && PACK_EXPANSION_P (TREE_VALUE (t))))
12959 /* We have pack expansions, so expand those and
12960 create a new list out of it. */
12961 tree purposevec = NULL_TREE;
12962 tree valuevec = NULL_TREE;
12966 /* Expand the argument expressions. */
12967 if (TREE_PURPOSE (t))
12968 purposevec = tsubst_pack_expansion (TREE_PURPOSE (t), args,
12969 complain, in_decl);
12970 if (TREE_VALUE (t))
12971 valuevec = tsubst_pack_expansion (TREE_VALUE (t), args,
12972 complain, in_decl);
12974 /* Build the rest of the list. */
12975 chain = TREE_CHAIN (t);
12976 if (chain && chain != void_type_node)
12977 chain = RECUR (chain);
12979 /* Determine the number of arguments. */
12980 if (purposevec && TREE_CODE (purposevec) == TREE_VEC)
12982 len = TREE_VEC_LENGTH (purposevec);
12983 gcc_assert (!valuevec || len == TREE_VEC_LENGTH (valuevec));
12985 else if (TREE_CODE (valuevec) == TREE_VEC)
12986 len = TREE_VEC_LENGTH (valuevec);
12989 /* Since we only performed a partial substitution into
12990 the argument pack, we only return a single list
12992 if (purposevec == TREE_PURPOSE (t)
12993 && valuevec == TREE_VALUE (t)
12994 && chain == TREE_CHAIN (t))
12997 return tree_cons (purposevec, valuevec, chain);
13000 /* Convert the argument vectors into a TREE_LIST */
13004 /* Grab the Ith values. */
13006 purpose = purposevec ? TREE_VEC_ELT (purposevec, i)
13009 = valuevec ? convert_from_reference (TREE_VEC_ELT (valuevec, i))
13012 /* Build the list (backwards). */
13013 chain = tree_cons (purpose, value, chain);
13019 purpose = TREE_PURPOSE (t);
13021 purpose = RECUR (purpose);
13022 value = TREE_VALUE (t);
13024 value = RECUR (value);
13025 chain = TREE_CHAIN (t);
13026 if (chain && chain != void_type_node)
13027 chain = RECUR (chain);
13028 if (purpose == TREE_PURPOSE (t)
13029 && value == TREE_VALUE (t)
13030 && chain == TREE_CHAIN (t))
13032 return tree_cons (purpose, value, chain);
13035 case COMPONENT_REF:
13041 object = tsubst_non_call_postfix_expression (TREE_OPERAND (t, 0),
13042 args, complain, in_decl);
13043 /* Remember that there was a reference to this entity. */
13044 if (DECL_P (object))
13045 mark_used (object);
13046 object_type = TREE_TYPE (object);
13048 member = TREE_OPERAND (t, 1);
13049 if (BASELINK_P (member))
13050 member = tsubst_baselink (member,
13051 non_reference (TREE_TYPE (object)),
13052 args, complain, in_decl);
13054 member = tsubst_copy (member, args, complain, in_decl);
13055 if (member == error_mark_node)
13056 return error_mark_node;
13058 if (object_type && !CLASS_TYPE_P (object_type))
13060 if (SCALAR_TYPE_P (object_type))
13062 tree s = NULL_TREE;
13063 tree dtor = member;
13065 if (TREE_CODE (dtor) == SCOPE_REF)
13067 s = TREE_OPERAND (dtor, 0);
13068 dtor = TREE_OPERAND (dtor, 1);
13070 if (TREE_CODE (dtor) == BIT_NOT_EXPR)
13072 dtor = TREE_OPERAND (dtor, 0);
13074 return finish_pseudo_destructor_expr (object, s, dtor);
13078 else if (TREE_CODE (member) == SCOPE_REF
13079 && TREE_CODE (TREE_OPERAND (member, 1)) == TEMPLATE_ID_EXPR)
13084 /* Lookup the template functions now that we know what the
13086 tmpl = TREE_OPERAND (TREE_OPERAND (member, 1), 0);
13087 args = TREE_OPERAND (TREE_OPERAND (member, 1), 1);
13088 member = lookup_qualified_name (TREE_OPERAND (member, 0), tmpl,
13089 /*is_type_p=*/false,
13090 /*complain=*/false);
13091 if (BASELINK_P (member))
13093 BASELINK_FUNCTIONS (member)
13094 = build_nt (TEMPLATE_ID_EXPR, BASELINK_FUNCTIONS (member),
13096 member = (adjust_result_of_qualified_name_lookup
13097 (member, BINFO_TYPE (BASELINK_BINFO (member)),
13102 qualified_name_lookup_error (object_type, tmpl, member,
13104 return error_mark_node;
13107 else if (TREE_CODE (member) == SCOPE_REF
13108 && !CLASS_TYPE_P (TREE_OPERAND (member, 0))
13109 && TREE_CODE (TREE_OPERAND (member, 0)) != NAMESPACE_DECL)
13111 if (complain & tf_error)
13113 if (TYPE_P (TREE_OPERAND (member, 0)))
13114 error ("%qT is not a class or namespace",
13115 TREE_OPERAND (member, 0));
13117 error ("%qD is not a class or namespace",
13118 TREE_OPERAND (member, 0));
13120 return error_mark_node;
13122 else if (TREE_CODE (member) == FIELD_DECL)
13123 return finish_non_static_data_member (member, object, NULL_TREE);
13125 return finish_class_member_access_expr (object, member,
13126 /*template_p=*/false,
13132 (RECUR (TREE_OPERAND (t, 0)));
13136 VEC(constructor_elt,gc) *n;
13137 constructor_elt *ce;
13138 unsigned HOST_WIDE_INT idx;
13139 tree type = tsubst (TREE_TYPE (t), args, complain, in_decl);
13140 bool process_index_p;
13142 bool need_copy_p = false;
13145 if (type == error_mark_node)
13146 return error_mark_node;
13148 /* digest_init will do the wrong thing if we let it. */
13149 if (type && TYPE_PTRMEMFUNC_P (type))
13152 /* We do not want to process the index of aggregate
13153 initializers as they are identifier nodes which will be
13154 looked up by digest_init. */
13155 process_index_p = !(type && MAYBE_CLASS_TYPE_P (type));
13157 n = VEC_copy (constructor_elt, gc, CONSTRUCTOR_ELTS (t));
13158 newlen = VEC_length (constructor_elt, n);
13159 FOR_EACH_VEC_ELT (constructor_elt, n, idx, ce)
13161 if (ce->index && process_index_p)
13162 ce->index = RECUR (ce->index);
13164 if (PACK_EXPANSION_P (ce->value))
13166 /* Substitute into the pack expansion. */
13167 ce->value = tsubst_pack_expansion (ce->value, args, complain,
13170 if (ce->value == error_mark_node)
13172 else if (TREE_VEC_LENGTH (ce->value) == 1)
13173 /* Just move the argument into place. */
13174 ce->value = TREE_VEC_ELT (ce->value, 0);
13177 /* Update the length of the final CONSTRUCTOR
13178 arguments vector, and note that we will need to
13180 newlen = newlen + TREE_VEC_LENGTH (ce->value) - 1;
13181 need_copy_p = true;
13185 ce->value = RECUR (ce->value);
13190 VEC(constructor_elt,gc) *old_n = n;
13192 n = VEC_alloc (constructor_elt, gc, newlen);
13193 FOR_EACH_VEC_ELT (constructor_elt, old_n, idx, ce)
13195 if (TREE_CODE (ce->value) == TREE_VEC)
13197 int i, len = TREE_VEC_LENGTH (ce->value);
13198 for (i = 0; i < len; ++i)
13199 CONSTRUCTOR_APPEND_ELT (n, 0,
13200 TREE_VEC_ELT (ce->value, i));
13203 CONSTRUCTOR_APPEND_ELT (n, 0, ce->value);
13207 r = build_constructor (init_list_type_node, n);
13208 CONSTRUCTOR_IS_DIRECT_INIT (r) = CONSTRUCTOR_IS_DIRECT_INIT (t);
13210 if (TREE_HAS_CONSTRUCTOR (t))
13211 return finish_compound_literal (type, r);
13213 TREE_TYPE (r) = type;
13219 tree operand_0 = TREE_OPERAND (t, 0);
13220 if (TYPE_P (operand_0))
13222 operand_0 = tsubst (operand_0, args, complain, in_decl);
13223 return get_typeid (operand_0);
13227 operand_0 = RECUR (operand_0);
13228 return build_typeid (operand_0);
13239 tree r = tsubst_copy (t, args, complain, in_decl);
13241 if (TREE_CODE (TREE_TYPE (t)) != REFERENCE_TYPE)
13242 /* If the original type was a reference, we'll be wrapped in
13243 the appropriate INDIRECT_REF. */
13244 r = convert_from_reference (r);
13249 return build_x_va_arg (RECUR (TREE_OPERAND (t, 0)),
13250 tsubst (TREE_TYPE (t), args, complain, in_decl));
13252 case OFFSETOF_EXPR:
13253 return finish_offsetof (RECUR (TREE_OPERAND (t, 0)));
13257 tree type1 = tsubst_copy (TRAIT_EXPR_TYPE1 (t), args,
13258 complain, in_decl);
13260 tree type2 = TRAIT_EXPR_TYPE2 (t);
13262 type2 = tsubst_copy (type2, args, complain, in_decl);
13264 return finish_trait_expr (TRAIT_EXPR_KIND (t), type1, type2);
13269 tree old_stmt_expr = cur_stmt_expr;
13270 tree stmt_expr = begin_stmt_expr ();
13272 cur_stmt_expr = stmt_expr;
13273 tsubst_expr (STMT_EXPR_STMT (t), args, complain, in_decl,
13274 integral_constant_expression_p);
13275 stmt_expr = finish_stmt_expr (stmt_expr, false);
13276 cur_stmt_expr = old_stmt_expr;
13278 /* If the resulting list of expression statement is empty,
13279 fold it further into void_zero_node. */
13280 if (empty_expr_stmt_p (stmt_expr))
13281 stmt_expr = void_zero_node;
13287 t = tsubst_copy (t, args, complain, in_decl);
13288 /* As in finish_id_expression, we resolve enumeration constants
13289 to their underlying values. */
13290 if (TREE_CODE (t) == CONST_DECL)
13292 used_types_insert (TREE_TYPE (t));
13293 return DECL_INITIAL (t);
13299 tree r = build_lambda_expr ();
13301 tree type = tsubst (TREE_TYPE (t), args, complain, NULL_TREE);
13302 TREE_TYPE (r) = type;
13303 CLASSTYPE_LAMBDA_EXPR (type) = r;
13305 LAMBDA_EXPR_LOCATION (r)
13306 = LAMBDA_EXPR_LOCATION (t);
13307 LAMBDA_EXPR_DEFAULT_CAPTURE_MODE (r)
13308 = LAMBDA_EXPR_DEFAULT_CAPTURE_MODE (t);
13309 LAMBDA_EXPR_MUTABLE_P (r) = LAMBDA_EXPR_MUTABLE_P (t);
13310 LAMBDA_EXPR_DISCRIMINATOR (r)
13311 = (LAMBDA_EXPR_DISCRIMINATOR (t));
13312 LAMBDA_EXPR_CAPTURE_LIST (r)
13313 = RECUR (LAMBDA_EXPR_CAPTURE_LIST (t));
13314 LAMBDA_EXPR_THIS_CAPTURE (r)
13315 = RECUR (LAMBDA_EXPR_THIS_CAPTURE (t));
13316 LAMBDA_EXPR_EXTRA_SCOPE (r)
13317 = RECUR (LAMBDA_EXPR_EXTRA_SCOPE (t));
13319 /* Do this again now that LAMBDA_EXPR_EXTRA_SCOPE is set. */
13320 determine_visibility (TYPE_NAME (type));
13321 /* Now that we know visibility, instantiate the type so we have a
13322 declaration of the op() for later calls to lambda_function. */
13323 complete_type (type);
13325 type = tsubst (LAMBDA_EXPR_RETURN_TYPE (t), args, complain, in_decl);
13327 apply_lambda_return_type (r, type);
13329 return build_lambda_object (r);
13333 /* We can get here for a constant initializer of non-dependent type.
13334 FIXME stop folding in cp_parser_initializer_clause. */
13335 gcc_assert (TREE_CONSTANT (t));
13336 return get_target_expr (RECUR (TARGET_EXPR_INITIAL (t)));
13339 /* Handle Objective-C++ constructs, if appropriate. */
13342 = objcp_tsubst_copy_and_build (t, args, complain,
13343 in_decl, /*function_p=*/false);
13347 return tsubst_copy (t, args, complain, in_decl);
13353 /* Verify that the instantiated ARGS are valid. For type arguments,
13354 make sure that the type's linkage is ok. For non-type arguments,
13355 make sure they are constants if they are integral or enumerations.
13356 Emit an error under control of COMPLAIN, and return TRUE on error. */
13359 check_instantiated_arg (tree tmpl, tree t, tsubst_flags_t complain)
13361 if (ARGUMENT_PACK_P (t))
13363 tree vec = ARGUMENT_PACK_ARGS (t);
13364 int len = TREE_VEC_LENGTH (vec);
13365 bool result = false;
13368 for (i = 0; i < len; ++i)
13369 if (check_instantiated_arg (tmpl, TREE_VEC_ELT (vec, i), complain))
13373 else if (TYPE_P (t))
13375 /* [basic.link]: A name with no linkage (notably, the name
13376 of a class or enumeration declared in a local scope)
13377 shall not be used to declare an entity with linkage.
13378 This implies that names with no linkage cannot be used as
13381 DR 757 relaxes this restriction for C++0x. */
13382 tree nt = (cxx_dialect > cxx98 ? NULL_TREE
13383 : no_linkage_check (t, /*relaxed_p=*/false));
13387 /* DR 488 makes use of a type with no linkage cause
13388 type deduction to fail. */
13389 if (complain & tf_error)
13391 if (TYPE_ANONYMOUS_P (nt))
13392 error ("%qT is/uses anonymous type", t);
13394 error ("template argument for %qD uses local type %qT",
13399 /* In order to avoid all sorts of complications, we do not
13400 allow variably-modified types as template arguments. */
13401 else if (variably_modified_type_p (t, NULL_TREE))
13403 if (complain & tf_error)
13404 error ("%qT is a variably modified type", t);
13408 /* A non-type argument of integral or enumerated type must be a
13410 else if (TREE_TYPE (t)
13411 && INTEGRAL_OR_ENUMERATION_TYPE_P (TREE_TYPE (t))
13412 && !TREE_CONSTANT (t))
13414 if (complain & tf_error)
13415 error ("integral expression %qE is not constant", t);
13422 check_instantiated_args (tree tmpl, tree args, tsubst_flags_t complain)
13424 int ix, len = DECL_NTPARMS (tmpl);
13425 bool result = false;
13427 for (ix = 0; ix != len; ix++)
13429 if (check_instantiated_arg (tmpl, TREE_VEC_ELT (args, ix), complain))
13432 if (result && (complain & tf_error))
13433 error (" trying to instantiate %qD", tmpl);
13437 /* Instantiate the indicated variable or function template TMPL with
13438 the template arguments in TARG_PTR. */
13441 instantiate_template (tree tmpl, tree orig_args, tsubst_flags_t complain)
13443 tree targ_ptr = orig_args;
13447 HOST_WIDE_INT saved_processing_template_decl;
13449 if (tmpl == error_mark_node)
13450 return error_mark_node;
13452 gcc_assert (TREE_CODE (tmpl) == TEMPLATE_DECL);
13454 /* If this function is a clone, handle it specially. */
13455 if (DECL_CLONED_FUNCTION_P (tmpl))
13460 /* Use DECL_ABSTRACT_ORIGIN because only FUNCTION_DECLs have
13461 DECL_CLONED_FUNCTION. */
13462 spec = instantiate_template (DECL_ABSTRACT_ORIGIN (tmpl),
13463 targ_ptr, complain);
13464 if (spec == error_mark_node)
13465 return error_mark_node;
13467 /* Look for the clone. */
13468 FOR_EACH_CLONE (clone, spec)
13469 if (DECL_NAME (clone) == DECL_NAME (tmpl))
13471 /* We should always have found the clone by now. */
13472 gcc_unreachable ();
13476 /* Check to see if we already have this specialization. */
13477 gen_tmpl = most_general_template (tmpl);
13478 if (tmpl != gen_tmpl)
13479 /* The TMPL is a partial instantiation. To get a full set of
13480 arguments we must add the arguments used to perform the
13481 partial instantiation. */
13482 targ_ptr = add_outermost_template_args (DECL_TI_ARGS (tmpl),
13485 /* It would be nice to avoid hashing here and then again in tsubst_decl,
13486 but it doesn't seem to be on the hot path. */
13487 spec = retrieve_specialization (gen_tmpl, targ_ptr, 0);
13489 gcc_assert (tmpl == gen_tmpl
13490 || ((fndecl = retrieve_specialization (tmpl, orig_args, 0))
13492 || fndecl == NULL_TREE);
13494 if (spec != NULL_TREE)
13497 if (check_instantiated_args (gen_tmpl, INNERMOST_TEMPLATE_ARGS (targ_ptr),
13499 return error_mark_node;
13501 /* We are building a FUNCTION_DECL, during which the access of its
13502 parameters and return types have to be checked. However this
13503 FUNCTION_DECL which is the desired context for access checking
13504 is not built yet. We solve this chicken-and-egg problem by
13505 deferring all checks until we have the FUNCTION_DECL. */
13506 push_deferring_access_checks (dk_deferred);
13508 /* Although PROCESSING_TEMPLATE_DECL may be true at this point
13509 (because, for example, we have encountered a non-dependent
13510 function call in the body of a template function and must now
13511 determine which of several overloaded functions will be called),
13512 within the instantiation itself we are not processing a
13514 saved_processing_template_decl = processing_template_decl;
13515 processing_template_decl = 0;
13516 /* Substitute template parameters to obtain the specialization. */
13517 fndecl = tsubst (DECL_TEMPLATE_RESULT (gen_tmpl),
13518 targ_ptr, complain, gen_tmpl);
13519 processing_template_decl = saved_processing_template_decl;
13520 if (fndecl == error_mark_node)
13521 return error_mark_node;
13523 /* Now we know the specialization, compute access previously
13525 push_access_scope (fndecl);
13527 /* Some typedefs referenced from within the template code need to be access
13528 checked at template instantiation time, i.e now. These types were
13529 added to the template at parsing time. Let's get those and perfom
13530 the acces checks then. */
13531 perform_typedefs_access_check (DECL_TEMPLATE_RESULT (tmpl), targ_ptr);
13532 perform_deferred_access_checks ();
13533 pop_access_scope (fndecl);
13534 pop_deferring_access_checks ();
13536 /* The DECL_TI_TEMPLATE should always be the immediate parent
13537 template, not the most general template. */
13538 DECL_TI_TEMPLATE (fndecl) = tmpl;
13540 /* If we've just instantiated the main entry point for a function,
13541 instantiate all the alternate entry points as well. We do this
13542 by cloning the instantiation of the main entry point, not by
13543 instantiating the template clones. */
13544 if (DECL_CHAIN (gen_tmpl) && DECL_CLONED_FUNCTION_P (DECL_CHAIN (gen_tmpl)))
13545 clone_function_decl (fndecl, /*update_method_vec_p=*/0);
13550 /* The FN is a TEMPLATE_DECL for a function. ARGS is an array with
13551 NARGS elements of the arguments that are being used when calling
13552 it. TARGS is a vector into which the deduced template arguments
13555 Return zero for success, 2 for an incomplete match that doesn't resolve
13556 all the types, and 1 for complete failure. An error message will be
13557 printed only for an incomplete match.
13559 If FN is a conversion operator, or we are trying to produce a specific
13560 specialization, RETURN_TYPE is the return type desired.
13562 The EXPLICIT_TARGS are explicit template arguments provided via a
13565 The parameter STRICT is one of:
13568 We are deducing arguments for a function call, as in
13569 [temp.deduct.call].
13572 We are deducing arguments for a conversion function, as in
13573 [temp.deduct.conv].
13576 We are deducing arguments when doing an explicit instantiation
13577 as in [temp.explicit], when determining an explicit specialization
13578 as in [temp.expl.spec], or when taking the address of a function
13579 template, as in [temp.deduct.funcaddr]. */
13582 fn_type_unification (tree fn,
13583 tree explicit_targs,
13586 unsigned int nargs,
13588 unification_kind_t strict,
13594 bool incomplete_argument_packs_p = false;
13596 gcc_assert (TREE_CODE (fn) == TEMPLATE_DECL);
13598 fntype = TREE_TYPE (fn);
13599 if (explicit_targs)
13603 The specified template arguments must match the template
13604 parameters in kind (i.e., type, nontype, template), and there
13605 must not be more arguments than there are parameters;
13606 otherwise type deduction fails.
13608 Nontype arguments must match the types of the corresponding
13609 nontype template parameters, or must be convertible to the
13610 types of the corresponding nontype parameters as specified in
13611 _temp.arg.nontype_, otherwise type deduction fails.
13613 All references in the function type of the function template
13614 to the corresponding template parameters are replaced by the
13615 specified template argument values. If a substitution in a
13616 template parameter or in the function type of the function
13617 template results in an invalid type, type deduction fails. */
13618 tree tparms = DECL_INNERMOST_TEMPLATE_PARMS (fn);
13619 int i, len = TREE_VEC_LENGTH (tparms);
13620 tree converted_args;
13621 bool incomplete = false;
13623 if (explicit_targs == error_mark_node)
13627 = (coerce_template_parms (tparms, explicit_targs, NULL_TREE, tf_none,
13628 /*require_all_args=*/false,
13629 /*use_default_args=*/false));
13630 if (converted_args == error_mark_node)
13633 /* Substitute the explicit args into the function type. This is
13634 necessary so that, for instance, explicitly declared function
13635 arguments can match null pointed constants. If we were given
13636 an incomplete set of explicit args, we must not do semantic
13637 processing during substitution as we could create partial
13639 for (i = 0; i < len; i++)
13641 tree parm = TREE_VALUE (TREE_VEC_ELT (tparms, i));
13642 bool parameter_pack = false;
13644 /* Dig out the actual parm. */
13645 if (TREE_CODE (parm) == TYPE_DECL
13646 || TREE_CODE (parm) == TEMPLATE_DECL)
13648 parm = TREE_TYPE (parm);
13649 parameter_pack = TEMPLATE_TYPE_PARAMETER_PACK (parm);
13651 else if (TREE_CODE (parm) == PARM_DECL)
13653 parm = DECL_INITIAL (parm);
13654 parameter_pack = TEMPLATE_PARM_PARAMETER_PACK (parm);
13657 if (parameter_pack)
13661 template_parm_level_and_index (parm, &level, &idx);
13663 /* Mark the argument pack as "incomplete". We could
13664 still deduce more arguments during unification. */
13665 targ = TMPL_ARG (converted_args, level, idx);
13668 ARGUMENT_PACK_INCOMPLETE_P(targ) = 1;
13669 ARGUMENT_PACK_EXPLICIT_ARGS (targ)
13670 = ARGUMENT_PACK_ARGS (targ);
13673 /* We have some incomplete argument packs. */
13674 incomplete_argument_packs_p = true;
13678 if (incomplete_argument_packs_p)
13679 /* Any substitution is guaranteed to be incomplete if there
13680 are incomplete argument packs, because we can still deduce
13684 incomplete = NUM_TMPL_ARGS (explicit_targs) != NUM_TMPL_ARGS (targs);
13686 processing_template_decl += incomplete;
13687 fntype = tsubst (fntype, converted_args, tf_none, NULL_TREE);
13688 processing_template_decl -= incomplete;
13690 if (fntype == error_mark_node)
13693 /* Place the explicitly specified arguments in TARGS. */
13694 for (i = NUM_TMPL_ARGS (converted_args); i--;)
13695 TREE_VEC_ELT (targs, i) = TREE_VEC_ELT (converted_args, i);
13698 /* Never do unification on the 'this' parameter. */
13699 parms = skip_artificial_parms_for (fn, TYPE_ARG_TYPES (fntype));
13705 parms = tree_cons (NULL_TREE, TREE_TYPE (fntype), parms);
13706 new_args = XALLOCAVEC (tree, nargs + 1);
13707 new_args[0] = return_type;
13708 memcpy (new_args + 1, args, nargs * sizeof (tree));
13713 /* We allow incomplete unification without an error message here
13714 because the standard doesn't seem to explicitly prohibit it. Our
13715 callers must be ready to deal with unification failures in any
13717 result = type_unification_real (DECL_INNERMOST_TEMPLATE_PARMS (fn),
13718 targs, parms, args, nargs, /*subr=*/0,
13721 if (result == 0 && incomplete_argument_packs_p)
13723 int i, len = NUM_TMPL_ARGS (targs);
13725 /* Clear the "incomplete" flags on all argument packs. */
13726 for (i = 0; i < len; i++)
13728 tree arg = TREE_VEC_ELT (targs, i);
13729 if (ARGUMENT_PACK_P (arg))
13731 ARGUMENT_PACK_INCOMPLETE_P (arg) = 0;
13732 ARGUMENT_PACK_EXPLICIT_ARGS (arg) = NULL_TREE;
13737 /* Now that we have bindings for all of the template arguments,
13738 ensure that the arguments deduced for the template template
13739 parameters have compatible template parameter lists. We cannot
13740 check this property before we have deduced all template
13741 arguments, because the template parameter types of a template
13742 template parameter might depend on prior template parameters
13743 deduced after the template template parameter. The following
13744 ill-formed example illustrates this issue:
13746 template<typename T, template<T> class C> void f(C<5>, T);
13748 template<int N> struct X {};
13751 f(X<5>(), 5l); // error: template argument deduction fails
13754 The template parameter list of 'C' depends on the template type
13755 parameter 'T', but 'C' is deduced to 'X' before 'T' is deduced to
13756 'long'. Thus, we can't check that 'C' cannot bind to 'X' at the
13757 time that we deduce 'C'. */
13759 && !template_template_parm_bindings_ok_p
13760 (DECL_INNERMOST_TEMPLATE_PARMS (fn), targs))
13764 /* All is well so far. Now, check:
13768 When all template arguments have been deduced, all uses of
13769 template parameters in nondeduced contexts are replaced with
13770 the corresponding deduced argument values. If the
13771 substitution results in an invalid type, as described above,
13772 type deduction fails. */
13774 tree substed = tsubst (TREE_TYPE (fn), targs, tf_none, NULL_TREE);
13775 if (substed == error_mark_node)
13778 /* If we're looking for an exact match, check that what we got
13779 is indeed an exact match. It might not be if some template
13780 parameters are used in non-deduced contexts. */
13781 if (strict == DEDUCE_EXACT)
13786 = skip_artificial_parms_for (fn, TYPE_ARG_TYPES (substed));
13788 sarg = tree_cons (NULL_TREE, TREE_TYPE (substed), sarg);
13789 for (i = 0; i < nargs && sarg; ++i, sarg = TREE_CHAIN (sarg))
13790 if (!same_type_p (args[i], TREE_VALUE (sarg)))
13798 /* Adjust types before performing type deduction, as described in
13799 [temp.deduct.call] and [temp.deduct.conv]. The rules in these two
13800 sections are symmetric. PARM is the type of a function parameter
13801 or the return type of the conversion function. ARG is the type of
13802 the argument passed to the call, or the type of the value
13803 initialized with the result of the conversion function.
13804 ARG_EXPR is the original argument expression, which may be null. */
13807 maybe_adjust_types_for_deduction (unification_kind_t strict,
13821 /* Swap PARM and ARG throughout the remainder of this
13822 function; the handling is precisely symmetric since PARM
13823 will initialize ARG rather than vice versa. */
13831 /* Core issue #873: Do the DR606 thing (see below) for these cases,
13832 too, but here handle it by stripping the reference from PARM
13833 rather than by adding it to ARG. */
13834 if (TREE_CODE (*parm) == REFERENCE_TYPE
13835 && TYPE_REF_IS_RVALUE (*parm)
13836 && TREE_CODE (TREE_TYPE (*parm)) == TEMPLATE_TYPE_PARM
13837 && cp_type_quals (TREE_TYPE (*parm)) == TYPE_UNQUALIFIED
13838 && TREE_CODE (*arg) == REFERENCE_TYPE
13839 && !TYPE_REF_IS_RVALUE (*arg))
13840 *parm = TREE_TYPE (*parm);
13841 /* Nothing else to do in this case. */
13845 gcc_unreachable ();
13848 if (TREE_CODE (*parm) != REFERENCE_TYPE)
13850 /* [temp.deduct.call]
13852 If P is not a reference type:
13854 --If A is an array type, the pointer type produced by the
13855 array-to-pointer standard conversion (_conv.array_) is
13856 used in place of A for type deduction; otherwise,
13858 --If A is a function type, the pointer type produced by
13859 the function-to-pointer standard conversion
13860 (_conv.func_) is used in place of A for type deduction;
13863 --If A is a cv-qualified type, the top level
13864 cv-qualifiers of A's type are ignored for type
13866 if (TREE_CODE (*arg) == ARRAY_TYPE)
13867 *arg = build_pointer_type (TREE_TYPE (*arg));
13868 else if (TREE_CODE (*arg) == FUNCTION_TYPE)
13869 *arg = build_pointer_type (*arg);
13871 *arg = TYPE_MAIN_VARIANT (*arg);
13874 /* From C++0x [14.8.2.1/3 temp.deduct.call] (after DR606), "If P is
13875 of the form T&&, where T is a template parameter, and the argument
13876 is an lvalue, T is deduced as A& */
13877 if (TREE_CODE (*parm) == REFERENCE_TYPE
13878 && TYPE_REF_IS_RVALUE (*parm)
13879 && TREE_CODE (TREE_TYPE (*parm)) == TEMPLATE_TYPE_PARM
13880 && cp_type_quals (TREE_TYPE (*parm)) == TYPE_UNQUALIFIED
13881 && arg_expr && real_lvalue_p (arg_expr))
13882 *arg = build_reference_type (*arg);
13884 /* [temp.deduct.call]
13886 If P is a cv-qualified type, the top level cv-qualifiers
13887 of P's type are ignored for type deduction. If P is a
13888 reference type, the type referred to by P is used for
13890 *parm = TYPE_MAIN_VARIANT (*parm);
13891 if (TREE_CODE (*parm) == REFERENCE_TYPE)
13893 *parm = TREE_TYPE (*parm);
13894 result |= UNIFY_ALLOW_OUTER_MORE_CV_QUAL;
13897 /* DR 322. For conversion deduction, remove a reference type on parm
13898 too (which has been swapped into ARG). */
13899 if (strict == DEDUCE_CONV && TREE_CODE (*arg) == REFERENCE_TYPE)
13900 *arg = TREE_TYPE (*arg);
13905 /* Most parms like fn_type_unification.
13907 If SUBR is 1, we're being called recursively (to unify the
13908 arguments of a function or method parameter of a function
13912 type_unification_real (tree tparms,
13916 unsigned int xnargs,
13918 unification_kind_t strict,
13921 tree parm, arg, arg_expr;
13923 int ntparms = TREE_VEC_LENGTH (tparms);
13925 int saw_undeduced = 0;
13928 unsigned int nargs;
13931 gcc_assert (TREE_CODE (tparms) == TREE_VEC);
13932 gcc_assert (xparms == NULL_TREE || TREE_CODE (xparms) == TREE_LIST);
13933 gcc_assert (ntparms > 0);
13935 /* Reset the number of non-defaulted template arguments contained
13937 NON_DEFAULT_TEMPLATE_ARGS_COUNT (targs) = NULL_TREE;
13942 sub_strict = (UNIFY_ALLOW_OUTER_LEVEL | UNIFY_ALLOW_MORE_CV_QUAL
13943 | UNIFY_ALLOW_DERIVED);
13947 sub_strict = UNIFY_ALLOW_LESS_CV_QUAL;
13951 sub_strict = UNIFY_ALLOW_NONE;
13955 gcc_unreachable ();
13964 while (parms && parms != void_list_node
13967 if (TREE_CODE (TREE_VALUE (parms)) == TYPE_PACK_EXPANSION)
13970 parm = TREE_VALUE (parms);
13971 parms = TREE_CHAIN (parms);
13976 if (arg == error_mark_node)
13978 if (arg == unknown_type_node)
13979 /* We can't deduce anything from this, but we might get all the
13980 template args from other function args. */
13983 /* Conversions will be performed on a function argument that
13984 corresponds with a function parameter that contains only
13985 non-deducible template parameters and explicitly specified
13986 template parameters. */
13987 if (!uses_template_parms (parm))
13992 type = TREE_TYPE (arg);
13996 if (same_type_p (parm, type))
13998 if (strict != DEDUCE_EXACT
13999 && can_convert_arg (parm, type, TYPE_P (arg) ? NULL_TREE : arg,
14008 gcc_assert (TREE_TYPE (arg) != NULL_TREE);
14009 if (type_unknown_p (arg))
14011 /* [temp.deduct.type]
14013 A template-argument can be deduced from a pointer to
14014 function or pointer to member function argument if
14015 the set of overloaded functions does not contain
14016 function templates and at most one of a set of
14017 overloaded functions provides a unique match. */
14018 if (resolve_overloaded_unification
14019 (tparms, targs, parm, arg, strict, sub_strict))
14025 arg = unlowered_expr_type (arg);
14026 if (arg == error_mark_node)
14031 int arg_strict = sub_strict;
14034 arg_strict |= maybe_adjust_types_for_deduction (strict, &parm, &arg,
14037 if (arg == init_list_type_node && arg_expr)
14039 if (unify (tparms, targs, parm, arg, arg_strict))
14046 && parms != void_list_node
14047 && TREE_CODE (TREE_VALUE (parms)) == TYPE_PACK_EXPANSION)
14049 /* Unify the remaining arguments with the pack expansion type. */
14051 tree parmvec = make_tree_vec (1);
14053 /* Allocate a TREE_VEC and copy in all of the arguments */
14054 argvec = make_tree_vec (nargs - ia);
14055 for (i = 0; ia < nargs; ++ia, ++i)
14056 TREE_VEC_ELT (argvec, i) = args[ia];
14058 /* Copy the parameter into parmvec. */
14059 TREE_VEC_ELT (parmvec, 0) = TREE_VALUE (parms);
14060 if (unify_pack_expansion (tparms, targs, parmvec, argvec, strict,
14061 /*call_args_p=*/true, /*subr=*/subr))
14064 /* Advance to the end of the list of parameters. */
14065 parms = TREE_CHAIN (parms);
14068 /* Fail if we've reached the end of the parm list, and more args
14069 are present, and the parm list isn't variadic. */
14070 if (ia < nargs && parms == void_list_node)
14072 /* Fail if parms are left and they don't have default values. */
14073 if (parms && parms != void_list_node
14074 && TREE_PURPOSE (parms) == NULL_TREE)
14078 for (i = 0; i < ntparms; i++)
14079 if (!TREE_VEC_ELT (targs, i))
14083 if (TREE_VEC_ELT (tparms, i) == error_mark_node)
14086 tparm = TREE_VALUE (TREE_VEC_ELT (tparms, i));
14088 /* If this is an undeduced nontype parameter that depends on
14089 a type parameter, try another pass; its type may have been
14090 deduced from a later argument than the one from which
14091 this parameter can be deduced. */
14092 if (TREE_CODE (tparm) == PARM_DECL
14093 && uses_template_parms (TREE_TYPE (tparm))
14094 && !saw_undeduced++)
14097 /* Core issue #226 (C++0x) [temp.deduct]:
14099 If a template argument has not been deduced, its
14100 default template argument, if any, is used.
14102 When we are in C++98 mode, TREE_PURPOSE will either
14103 be NULL_TREE or ERROR_MARK_NODE, so we do not need
14104 to explicitly check cxx_dialect here. */
14105 if (TREE_PURPOSE (TREE_VEC_ELT (tparms, i)))
14107 tree parm = TREE_VALUE (TREE_VEC_ELT (tparms, i));
14108 tree arg = TREE_PURPOSE (TREE_VEC_ELT (tparms, i));
14109 arg = tsubst_template_arg (arg, targs, tf_none, NULL_TREE);
14110 arg = convert_template_argument (parm, arg, targs, tf_none,
14112 if (arg == error_mark_node)
14116 TREE_VEC_ELT (targs, i) = arg;
14117 /* The position of the first default template argument,
14118 is also the number of non-defaulted arguments in TARGS.
14120 if (!NON_DEFAULT_TEMPLATE_ARGS_COUNT (targs))
14121 SET_NON_DEFAULT_TEMPLATE_ARGS_COUNT (targs, i);
14126 /* If the type parameter is a parameter pack, then it will
14127 be deduced to an empty parameter pack. */
14128 if (template_parameter_pack_p (tparm))
14132 if (TREE_CODE (tparm) == TEMPLATE_PARM_INDEX)
14134 arg = make_node (NONTYPE_ARGUMENT_PACK);
14135 TREE_TYPE (arg) = TREE_TYPE (TEMPLATE_PARM_DECL (tparm));
14136 TREE_CONSTANT (arg) = 1;
14139 arg = cxx_make_type (TYPE_ARGUMENT_PACK);
14141 SET_ARGUMENT_PACK_ARGS (arg, make_tree_vec (0));
14143 TREE_VEC_ELT (targs, i) = arg;
14149 #ifdef ENABLE_CHECKING
14150 if (!NON_DEFAULT_TEMPLATE_ARGS_COUNT (targs))
14151 SET_NON_DEFAULT_TEMPLATE_ARGS_COUNT (targs, TREE_VEC_LENGTH (targs));
14157 /* Subroutine of type_unification_real. Args are like the variables
14158 at the call site. ARG is an overloaded function (or template-id);
14159 we try deducing template args from each of the overloads, and if
14160 only one succeeds, we go with that. Modifies TARGS and returns
14161 true on success. */
14164 resolve_overloaded_unification (tree tparms,
14168 unification_kind_t strict,
14171 tree tempargs = copy_node (targs);
14173 tree goodfn = NULL_TREE;
14176 if (TREE_CODE (arg) == ADDR_EXPR)
14178 arg = TREE_OPERAND (arg, 0);
14184 if (TREE_CODE (arg) == COMPONENT_REF)
14185 /* Handle `&x' where `x' is some static or non-static member
14187 arg = TREE_OPERAND (arg, 1);
14189 if (TREE_CODE (arg) == OFFSET_REF)
14190 arg = TREE_OPERAND (arg, 1);
14192 /* Strip baselink information. */
14193 if (BASELINK_P (arg))
14194 arg = BASELINK_FUNCTIONS (arg);
14196 if (TREE_CODE (arg) == TEMPLATE_ID_EXPR)
14198 /* If we got some explicit template args, we need to plug them into
14199 the affected templates before we try to unify, in case the
14200 explicit args will completely resolve the templates in question. */
14202 tree expl_subargs = TREE_OPERAND (arg, 1);
14203 arg = TREE_OPERAND (arg, 0);
14205 for (; arg; arg = OVL_NEXT (arg))
14207 tree fn = OVL_CURRENT (arg);
14208 tree subargs, elem;
14210 if (TREE_CODE (fn) != TEMPLATE_DECL)
14213 ++processing_template_decl;
14214 subargs = get_bindings (fn, DECL_TEMPLATE_RESULT (fn),
14215 expl_subargs, /*check_ret=*/false);
14218 elem = tsubst (TREE_TYPE (fn), subargs, tf_none, NULL_TREE);
14219 if (try_one_overload (tparms, targs, tempargs, parm,
14220 elem, strict, sub_strict, addr_p)
14221 && (!goodfn || !decls_match (goodfn, elem)))
14227 --processing_template_decl;
14230 else if (TREE_CODE (arg) != OVERLOAD
14231 && TREE_CODE (arg) != FUNCTION_DECL)
14232 /* If ARG is, for example, "(0, &f)" then its type will be unknown
14233 -- but the deduction does not succeed because the expression is
14234 not just the function on its own. */
14237 for (; arg; arg = OVL_NEXT (arg))
14238 if (try_one_overload (tparms, targs, tempargs, parm,
14239 TREE_TYPE (OVL_CURRENT (arg)),
14240 strict, sub_strict, addr_p)
14241 && (!goodfn || !decls_match (goodfn, OVL_CURRENT (arg))))
14243 goodfn = OVL_CURRENT (arg);
14247 /* [temp.deduct.type] A template-argument can be deduced from a pointer
14248 to function or pointer to member function argument if the set of
14249 overloaded functions does not contain function templates and at most
14250 one of a set of overloaded functions provides a unique match.
14252 So if we found multiple possibilities, we return success but don't
14253 deduce anything. */
14257 int i = TREE_VEC_LENGTH (targs);
14259 if (TREE_VEC_ELT (tempargs, i))
14260 TREE_VEC_ELT (targs, i) = TREE_VEC_ELT (tempargs, i);
14268 /* Core DR 115: In contexts where deduction is done and fails, or in
14269 contexts where deduction is not done, if a template argument list is
14270 specified and it, along with any default template arguments, identifies
14271 a single function template specialization, then the template-id is an
14272 lvalue for the function template specialization. */
14275 resolve_nondeduced_context (tree orig_expr)
14277 tree expr, offset, baselink;
14280 if (!type_unknown_p (orig_expr))
14285 offset = NULL_TREE;
14286 baselink = NULL_TREE;
14288 if (TREE_CODE (expr) == ADDR_EXPR)
14290 expr = TREE_OPERAND (expr, 0);
14293 if (TREE_CODE (expr) == OFFSET_REF)
14296 expr = TREE_OPERAND (expr, 1);
14298 if (TREE_CODE (expr) == BASELINK)
14301 expr = BASELINK_FUNCTIONS (expr);
14304 if (TREE_CODE (expr) == TEMPLATE_ID_EXPR)
14307 tree goodfn = NULL_TREE;
14309 /* If we got some explicit template args, we need to plug them into
14310 the affected templates before we try to unify, in case the
14311 explicit args will completely resolve the templates in question. */
14313 tree expl_subargs = TREE_OPERAND (expr, 1);
14314 tree arg = TREE_OPERAND (expr, 0);
14315 tree badfn = NULL_TREE;
14316 tree badargs = NULL_TREE;
14318 for (; arg; arg = OVL_NEXT (arg))
14320 tree fn = OVL_CURRENT (arg);
14321 tree subargs, elem;
14323 if (TREE_CODE (fn) != TEMPLATE_DECL)
14326 ++processing_template_decl;
14327 subargs = get_bindings (fn, DECL_TEMPLATE_RESULT (fn),
14328 expl_subargs, /*check_ret=*/false);
14329 if (subargs && !any_dependent_template_arguments_p (subargs))
14331 elem = instantiate_template (fn, subargs, tf_none);
14332 if (elem == error_mark_node)
14337 else if (elem && (!goodfn || !decls_match (goodfn, elem)))
14343 --processing_template_decl;
14349 expr = build_baselink (BASELINK_BINFO (baselink),
14350 BASELINK_ACCESS_BINFO (baselink),
14351 expr, BASELINK_OPTYPE (baselink));
14355 = TYPE_MAIN_VARIANT (TREE_TYPE (TREE_OPERAND (offset, 0)));
14356 expr = build_offset_ref (base, expr, addr);
14359 expr = cp_build_addr_expr (expr, tf_warning_or_error);
14362 else if (good == 0 && badargs)
14363 /* There were no good options and at least one bad one, so let the
14364 user know what the problem is. */
14365 instantiate_template (badfn, badargs, tf_warning_or_error);
14370 /* Subroutine of resolve_overloaded_unification; does deduction for a single
14371 overload. Fills TARGS with any deduced arguments, or error_mark_node if
14372 different overloads deduce different arguments for a given parm.
14373 ADDR_P is true if the expression for which deduction is being
14374 performed was of the form "& fn" rather than simply "fn".
14376 Returns 1 on success. */
14379 try_one_overload (tree tparms,
14384 unification_kind_t strict,
14392 /* [temp.deduct.type] A template-argument can be deduced from a pointer
14393 to function or pointer to member function argument if the set of
14394 overloaded functions does not contain function templates and at most
14395 one of a set of overloaded functions provides a unique match.
14397 So if this is a template, just return success. */
14399 if (uses_template_parms (arg))
14402 if (TREE_CODE (arg) == METHOD_TYPE)
14403 arg = build_ptrmemfunc_type (build_pointer_type (arg));
14405 arg = build_pointer_type (arg);
14407 sub_strict |= maybe_adjust_types_for_deduction (strict, &parm, &arg, NULL);
14409 /* We don't copy orig_targs for this because if we have already deduced
14410 some template args from previous args, unify would complain when we
14411 try to deduce a template parameter for the same argument, even though
14412 there isn't really a conflict. */
14413 nargs = TREE_VEC_LENGTH (targs);
14414 tempargs = make_tree_vec (nargs);
14416 if (unify (tparms, tempargs, parm, arg, sub_strict) != 0)
14419 /* First make sure we didn't deduce anything that conflicts with
14420 explicitly specified args. */
14421 for (i = nargs; i--; )
14423 tree elt = TREE_VEC_ELT (tempargs, i);
14424 tree oldelt = TREE_VEC_ELT (orig_targs, i);
14428 else if (uses_template_parms (elt))
14429 /* Since we're unifying against ourselves, we will fill in
14430 template args used in the function parm list with our own
14431 template parms. Discard them. */
14432 TREE_VEC_ELT (tempargs, i) = NULL_TREE;
14433 else if (oldelt && !template_args_equal (oldelt, elt))
14437 for (i = nargs; i--; )
14439 tree elt = TREE_VEC_ELT (tempargs, i);
14442 TREE_VEC_ELT (targs, i) = elt;
14448 /* PARM is a template class (perhaps with unbound template
14449 parameters). ARG is a fully instantiated type. If ARG can be
14450 bound to PARM, return ARG, otherwise return NULL_TREE. TPARMS and
14451 TARGS are as for unify. */
14454 try_class_unification (tree tparms, tree targs, tree parm, tree arg)
14456 tree copy_of_targs;
14458 if (!CLASSTYPE_TEMPLATE_INFO (arg)
14459 || (most_general_template (CLASSTYPE_TI_TEMPLATE (arg))
14460 != most_general_template (CLASSTYPE_TI_TEMPLATE (parm))))
14463 /* We need to make a new template argument vector for the call to
14464 unify. If we used TARGS, we'd clutter it up with the result of
14465 the attempted unification, even if this class didn't work out.
14466 We also don't want to commit ourselves to all the unifications
14467 we've already done, since unification is supposed to be done on
14468 an argument-by-argument basis. In other words, consider the
14469 following pathological case:
14471 template <int I, int J, int K>
14474 template <int I, int J>
14475 struct S<I, J, 2> : public S<I, I, I>, S<J, J, J> {};
14477 template <int I, int J, int K>
14478 void f(S<I, J, K>, S<I, I, I>);
14487 Now, by the time we consider the unification involving `s2', we
14488 already know that we must have `f<0, 0, 0>'. But, even though
14489 `S<0, 1, 2>' is derived from `S<0, 0, 0>', the code is invalid
14490 because there are two ways to unify base classes of S<0, 1, 2>
14491 with S<I, I, I>. If we kept the already deduced knowledge, we
14492 would reject the possibility I=1. */
14493 copy_of_targs = make_tree_vec (TREE_VEC_LENGTH (targs));
14495 /* If unification failed, we're done. */
14496 if (unify (tparms, copy_of_targs, CLASSTYPE_TI_ARGS (parm),
14497 CLASSTYPE_TI_ARGS (arg), UNIFY_ALLOW_NONE))
14503 /* Given a template type PARM and a class type ARG, find the unique
14504 base type in ARG that is an instance of PARM. We do not examine
14505 ARG itself; only its base-classes. If there is not exactly one
14506 appropriate base class, return NULL_TREE. PARM may be the type of
14507 a partial specialization, as well as a plain template type. Used
14511 get_template_base (tree tparms, tree targs, tree parm, tree arg)
14513 tree rval = NULL_TREE;
14516 gcc_assert (RECORD_OR_UNION_CODE_P (TREE_CODE (arg)));
14518 binfo = TYPE_BINFO (complete_type (arg));
14520 /* The type could not be completed. */
14523 /* Walk in inheritance graph order. The search order is not
14524 important, and this avoids multiple walks of virtual bases. */
14525 for (binfo = TREE_CHAIN (binfo); binfo; binfo = TREE_CHAIN (binfo))
14527 tree r = try_class_unification (tparms, targs, parm, BINFO_TYPE (binfo));
14531 /* If there is more than one satisfactory baseclass, then:
14535 If they yield more than one possible deduced A, the type
14539 if (rval && !same_type_p (r, rval))
14549 /* Returns the level of DECL, which declares a template parameter. */
14552 template_decl_level (tree decl)
14554 switch (TREE_CODE (decl))
14557 case TEMPLATE_DECL:
14558 return TEMPLATE_TYPE_LEVEL (TREE_TYPE (decl));
14561 return TEMPLATE_PARM_LEVEL (DECL_INITIAL (decl));
14564 gcc_unreachable ();
14569 /* Decide whether ARG can be unified with PARM, considering only the
14570 cv-qualifiers of each type, given STRICT as documented for unify.
14571 Returns nonzero iff the unification is OK on that basis. */
14574 check_cv_quals_for_unify (int strict, tree arg, tree parm)
14576 int arg_quals = cp_type_quals (arg);
14577 int parm_quals = cp_type_quals (parm);
14579 if (TREE_CODE (parm) == TEMPLATE_TYPE_PARM
14580 && !(strict & UNIFY_ALLOW_OUTER_MORE_CV_QUAL))
14582 /* Although a CVR qualifier is ignored when being applied to a
14583 substituted template parameter ([8.3.2]/1 for example), that
14584 does not allow us to unify "const T" with "int&" because both
14585 types are not of the form "cv-list T" [14.8.2.5 temp.deduct.type].
14586 It is ok when we're allowing additional CV qualifiers
14587 at the outer level [14.8.2.1]/3,1st bullet. */
14588 if ((TREE_CODE (arg) == REFERENCE_TYPE
14589 || TREE_CODE (arg) == FUNCTION_TYPE
14590 || TREE_CODE (arg) == METHOD_TYPE)
14591 && (parm_quals & (TYPE_QUAL_CONST | TYPE_QUAL_VOLATILE)))
14594 if ((!POINTER_TYPE_P (arg) && TREE_CODE (arg) != TEMPLATE_TYPE_PARM)
14595 && (parm_quals & TYPE_QUAL_RESTRICT))
14599 if (!(strict & (UNIFY_ALLOW_MORE_CV_QUAL | UNIFY_ALLOW_OUTER_MORE_CV_QUAL))
14600 && (arg_quals & parm_quals) != parm_quals)
14603 if (!(strict & (UNIFY_ALLOW_LESS_CV_QUAL | UNIFY_ALLOW_OUTER_LESS_CV_QUAL))
14604 && (parm_quals & arg_quals) != arg_quals)
14610 /* Determines the LEVEL and INDEX for the template parameter PARM. */
14612 template_parm_level_and_index (tree parm, int* level, int* index)
14614 if (TREE_CODE (parm) == TEMPLATE_TYPE_PARM
14615 || TREE_CODE (parm) == TEMPLATE_TEMPLATE_PARM
14616 || TREE_CODE (parm) == BOUND_TEMPLATE_TEMPLATE_PARM)
14618 *index = TEMPLATE_TYPE_IDX (parm);
14619 *level = TEMPLATE_TYPE_LEVEL (parm);
14623 *index = TEMPLATE_PARM_IDX (parm);
14624 *level = TEMPLATE_PARM_LEVEL (parm);
14628 /* Unifies the remaining arguments in PACKED_ARGS with the pack
14629 expansion at the end of PACKED_PARMS. Returns 0 if the type
14630 deduction succeeds, 1 otherwise. STRICT is the same as in
14631 unify. CALL_ARGS_P is true iff PACKED_ARGS is actually a function
14632 call argument list. We'll need to adjust the arguments to make them
14633 types. SUBR tells us if this is from a recursive call to
14634 type_unification_real. */
14636 unify_pack_expansion (tree tparms, tree targs, tree packed_parms,
14637 tree packed_args, int strict, bool call_args_p,
14641 = TREE_VEC_ELT (packed_parms, TREE_VEC_LENGTH (packed_parms) - 1);
14642 tree pattern = PACK_EXPANSION_PATTERN (parm);
14643 tree pack, packs = NULL_TREE;
14644 int i, start = TREE_VEC_LENGTH (packed_parms) - 1;
14645 int len = TREE_VEC_LENGTH (packed_args);
14647 /* Determine the parameter packs we will be deducing from the
14648 pattern, and record their current deductions. */
14649 for (pack = PACK_EXPANSION_PARAMETER_PACKS (parm);
14650 pack; pack = TREE_CHAIN (pack))
14652 tree parm_pack = TREE_VALUE (pack);
14655 /* Determine the index and level of this parameter pack. */
14656 template_parm_level_and_index (parm_pack, &level, &idx);
14658 /* Keep track of the parameter packs and their corresponding
14660 packs = tree_cons (parm_pack, TMPL_ARG (targs, level, idx), packs);
14661 TREE_TYPE (packs) = make_tree_vec (len - start);
14664 /* Loop through all of the arguments that have not yet been
14665 unified and unify each with the pattern. */
14666 for (i = start; i < len; i++)
14668 tree parm = pattern;
14670 /* For each parameter pack, clear out the deduced value so that
14671 we can deduce it again. */
14672 for (pack = packs; pack; pack = TREE_CHAIN (pack))
14675 template_parm_level_and_index (TREE_PURPOSE (pack), &level, &idx);
14677 TMPL_ARG (targs, level, idx) = NULL_TREE;
14680 /* Unify the pattern with the current argument. */
14682 tree arg = TREE_VEC_ELT (packed_args, i);
14683 tree arg_expr = NULL_TREE;
14684 int arg_strict = strict;
14685 bool skip_arg_p = false;
14691 /* This mirrors what we do in type_unification_real. */
14695 sub_strict = (UNIFY_ALLOW_OUTER_LEVEL
14696 | UNIFY_ALLOW_MORE_CV_QUAL
14697 | UNIFY_ALLOW_DERIVED);
14701 sub_strict = UNIFY_ALLOW_LESS_CV_QUAL;
14705 sub_strict = UNIFY_ALLOW_NONE;
14709 gcc_unreachable ();
14714 gcc_assert (TREE_TYPE (arg) != NULL_TREE);
14715 if (type_unknown_p (arg))
14717 /* [temp.deduct.type] A template-argument can be
14718 deduced from a pointer to function or pointer
14719 to member function argument if the set of
14720 overloaded functions does not contain function
14721 templates and at most one of a set of
14722 overloaded functions provides a unique
14725 if (resolve_overloaded_unification
14726 (tparms, targs, parm, arg,
14727 (unification_kind_t) strict,
14737 arg = unlowered_expr_type (arg);
14738 if (arg == error_mark_node)
14743 arg_strict = sub_strict;
14747 maybe_adjust_types_for_deduction ((unification_kind_t) strict,
14748 &parm, &arg, arg_expr);
14753 /* For deduction from an init-list we need the actual list. */
14754 if (arg_expr && BRACE_ENCLOSED_INITIALIZER_P (arg_expr))
14756 if (unify (tparms, targs, parm, arg, arg_strict))
14761 /* For each parameter pack, collect the deduced value. */
14762 for (pack = packs; pack; pack = TREE_CHAIN (pack))
14765 template_parm_level_and_index (TREE_PURPOSE (pack), &level, &idx);
14767 TREE_VEC_ELT (TREE_TYPE (pack), i - start) =
14768 TMPL_ARG (targs, level, idx);
14772 /* Verify that the results of unification with the parameter packs
14773 produce results consistent with what we've seen before, and make
14774 the deduced argument packs available. */
14775 for (pack = packs; pack; pack = TREE_CHAIN (pack))
14777 tree old_pack = TREE_VALUE (pack);
14778 tree new_args = TREE_TYPE (pack);
14779 int i, len = TREE_VEC_LENGTH (new_args);
14781 bool nondeduced_p = false;
14783 /* By default keep the original deduced argument pack.
14784 If necessary, more specific code is going to update the
14785 resulting deduced argument later down in this function. */
14786 template_parm_level_and_index (TREE_PURPOSE (pack), &level, &idx);
14787 TMPL_ARG (targs, level, idx) = old_pack;
14789 /* If NEW_ARGS contains any NULL_TREE entries, we didn't
14790 actually deduce anything. */
14791 for (i = 0; i < len && !nondeduced_p; ++i)
14792 if (TREE_VEC_ELT (new_args, i) == NULL_TREE)
14793 nondeduced_p = true;
14797 if (old_pack && ARGUMENT_PACK_INCOMPLETE_P (old_pack))
14799 /* Prepend the explicit arguments onto NEW_ARGS. */
14800 tree explicit_args = ARGUMENT_PACK_EXPLICIT_ARGS (old_pack);
14801 tree old_args = new_args;
14802 int i, explicit_len = TREE_VEC_LENGTH (explicit_args);
14803 int len = explicit_len + TREE_VEC_LENGTH (old_args);
14805 /* Copy the explicit arguments. */
14806 new_args = make_tree_vec (len);
14807 for (i = 0; i < explicit_len; i++)
14808 TREE_VEC_ELT (new_args, i) = TREE_VEC_ELT (explicit_args, i);
14810 /* Copy the deduced arguments. */
14811 for (; i < len; i++)
14812 TREE_VEC_ELT (new_args, i) =
14813 TREE_VEC_ELT (old_args, i - explicit_len);
14819 /* Build the deduced *_ARGUMENT_PACK. */
14820 if (TREE_CODE (TREE_PURPOSE (pack)) == TEMPLATE_PARM_INDEX)
14822 result = make_node (NONTYPE_ARGUMENT_PACK);
14823 TREE_TYPE (result) =
14824 TREE_TYPE (TEMPLATE_PARM_DECL (TREE_PURPOSE (pack)));
14825 TREE_CONSTANT (result) = 1;
14828 result = cxx_make_type (TYPE_ARGUMENT_PACK);
14830 SET_ARGUMENT_PACK_ARGS (result, new_args);
14832 /* Note the deduced argument packs for this parameter
14834 TMPL_ARG (targs, level, idx) = result;
14836 else if (ARGUMENT_PACK_INCOMPLETE_P (old_pack)
14837 && (ARGUMENT_PACK_ARGS (old_pack)
14838 == ARGUMENT_PACK_EXPLICIT_ARGS (old_pack)))
14840 /* We only had the explicitly-provided arguments before, but
14841 now we have a complete set of arguments. */
14842 tree explicit_args = ARGUMENT_PACK_EXPLICIT_ARGS (old_pack);
14844 SET_ARGUMENT_PACK_ARGS (old_pack, new_args);
14845 ARGUMENT_PACK_INCOMPLETE_P (old_pack) = 1;
14846 ARGUMENT_PACK_EXPLICIT_ARGS (old_pack) = explicit_args;
14848 else if (!comp_template_args (ARGUMENT_PACK_ARGS (old_pack),
14850 /* Inconsistent unification of this parameter pack. */
14857 /* Deduce the value of template parameters. TPARMS is the (innermost)
14858 set of template parameters to a template. TARGS is the bindings
14859 for those template parameters, as determined thus far; TARGS may
14860 include template arguments for outer levels of template parameters
14861 as well. PARM is a parameter to a template function, or a
14862 subcomponent of that parameter; ARG is the corresponding argument.
14863 This function attempts to match PARM with ARG in a manner
14864 consistent with the existing assignments in TARGS. If more values
14865 are deduced, then TARGS is updated.
14867 Returns 0 if the type deduction succeeds, 1 otherwise. The
14868 parameter STRICT is a bitwise or of the following flags:
14871 Require an exact match between PARM and ARG.
14872 UNIFY_ALLOW_MORE_CV_QUAL:
14873 Allow the deduced ARG to be more cv-qualified (by qualification
14874 conversion) than ARG.
14875 UNIFY_ALLOW_LESS_CV_QUAL:
14876 Allow the deduced ARG to be less cv-qualified than ARG.
14877 UNIFY_ALLOW_DERIVED:
14878 Allow the deduced ARG to be a template base class of ARG,
14879 or a pointer to a template base class of the type pointed to by
14881 UNIFY_ALLOW_INTEGER:
14882 Allow any integral type to be deduced. See the TEMPLATE_PARM_INDEX
14883 case for more information.
14884 UNIFY_ALLOW_OUTER_LEVEL:
14885 This is the outermost level of a deduction. Used to determine validity
14886 of qualification conversions. A valid qualification conversion must
14887 have const qualified pointers leading up to the inner type which
14888 requires additional CV quals, except at the outer level, where const
14889 is not required [conv.qual]. It would be normal to set this flag in
14890 addition to setting UNIFY_ALLOW_MORE_CV_QUAL.
14891 UNIFY_ALLOW_OUTER_MORE_CV_QUAL:
14892 This is the outermost level of a deduction, and PARM can be more CV
14893 qualified at this point.
14894 UNIFY_ALLOW_OUTER_LESS_CV_QUAL:
14895 This is the outermost level of a deduction, and PARM can be less CV
14896 qualified at this point. */
14899 unify (tree tparms, tree targs, tree parm, tree arg, int strict)
14904 int strict_in = strict;
14906 /* I don't think this will do the right thing with respect to types.
14907 But the only case I've seen it in so far has been array bounds, where
14908 signedness is the only information lost, and I think that will be
14910 while (TREE_CODE (parm) == NOP_EXPR)
14911 parm = TREE_OPERAND (parm, 0);
14913 if (arg == error_mark_node)
14915 if (arg == unknown_type_node
14916 || arg == init_list_type_node)
14917 /* We can't deduce anything from this, but we might get all the
14918 template args from other function args. */
14921 /* If PARM uses template parameters, then we can't bail out here,
14922 even if ARG == PARM, since we won't record unifications for the
14923 template parameters. We might need them if we're trying to
14924 figure out which of two things is more specialized. */
14925 if (arg == parm && !uses_template_parms (parm))
14928 /* Handle init lists early, so the rest of the function can assume
14929 we're dealing with a type. */
14930 if (BRACE_ENCLOSED_INITIALIZER_P (arg))
14934 tree orig_parm = parm;
14936 /* Replace T with std::initializer_list<T> for deduction. */
14937 if (TREE_CODE (parm) == TEMPLATE_TYPE_PARM
14938 && flag_deduce_init_list)
14939 parm = listify (parm);
14941 if (!is_std_init_list (parm))
14942 /* We can only deduce from an initializer list argument if the
14943 parameter is std::initializer_list; otherwise this is a
14944 non-deduced context. */
14947 elttype = TREE_VEC_ELT (CLASSTYPE_TI_ARGS (parm), 0);
14949 FOR_EACH_CONSTRUCTOR_VALUE (CONSTRUCTOR_ELTS (arg), i, elt)
14951 int elt_strict = strict;
14953 if (elt == error_mark_node)
14956 if (!BRACE_ENCLOSED_INITIALIZER_P (elt))
14958 tree type = TREE_TYPE (elt);
14959 /* It should only be possible to get here for a call. */
14960 gcc_assert (elt_strict & UNIFY_ALLOW_OUTER_LEVEL);
14961 elt_strict |= maybe_adjust_types_for_deduction
14962 (DEDUCE_CALL, &elttype, &type, elt);
14966 if (unify (tparms, targs, elttype, elt, elt_strict))
14970 /* If the std::initializer_list<T> deduction worked, replace the
14971 deduced A with std::initializer_list<A>. */
14972 if (orig_parm != parm)
14974 idx = TEMPLATE_TYPE_IDX (orig_parm);
14975 targ = TREE_VEC_ELT (INNERMOST_TEMPLATE_ARGS (targs), idx);
14976 targ = listify (targ);
14977 TREE_VEC_ELT (INNERMOST_TEMPLATE_ARGS (targs), idx) = targ;
14982 /* Immediately reject some pairs that won't unify because of
14983 cv-qualification mismatches. */
14984 if (TREE_CODE (arg) == TREE_CODE (parm)
14986 /* It is the elements of the array which hold the cv quals of an array
14987 type, and the elements might be template type parms. We'll check
14988 when we recurse. */
14989 && TREE_CODE (arg) != ARRAY_TYPE
14990 /* We check the cv-qualifiers when unifying with template type
14991 parameters below. We want to allow ARG `const T' to unify with
14992 PARM `T' for example, when computing which of two templates
14993 is more specialized, for example. */
14994 && TREE_CODE (arg) != TEMPLATE_TYPE_PARM
14995 && !check_cv_quals_for_unify (strict_in, arg, parm))
14998 if (!(strict & UNIFY_ALLOW_OUTER_LEVEL)
14999 && TYPE_P (parm) && !CP_TYPE_CONST_P (parm))
15000 strict &= ~UNIFY_ALLOW_MORE_CV_QUAL;
15001 strict &= ~UNIFY_ALLOW_OUTER_LEVEL;
15002 strict &= ~UNIFY_ALLOW_DERIVED;
15003 strict &= ~UNIFY_ALLOW_OUTER_MORE_CV_QUAL;
15004 strict &= ~UNIFY_ALLOW_OUTER_LESS_CV_QUAL;
15006 switch (TREE_CODE (parm))
15008 case TYPENAME_TYPE:
15010 case UNBOUND_CLASS_TEMPLATE:
15011 /* In a type which contains a nested-name-specifier, template
15012 argument values cannot be deduced for template parameters used
15013 within the nested-name-specifier. */
15016 case TEMPLATE_TYPE_PARM:
15017 case TEMPLATE_TEMPLATE_PARM:
15018 case BOUND_TEMPLATE_TEMPLATE_PARM:
15019 tparm = TREE_VALUE (TREE_VEC_ELT (tparms, 0));
15020 if (tparm == error_mark_node)
15023 if (TEMPLATE_TYPE_LEVEL (parm)
15024 != template_decl_level (tparm))
15025 /* The PARM is not one we're trying to unify. Just check
15026 to see if it matches ARG. */
15027 return (TREE_CODE (arg) == TREE_CODE (parm)
15028 && same_type_p (parm, arg)) ? 0 : 1;
15029 idx = TEMPLATE_TYPE_IDX (parm);
15030 targ = TREE_VEC_ELT (INNERMOST_TEMPLATE_ARGS (targs), idx);
15031 tparm = TREE_VALUE (TREE_VEC_ELT (tparms, idx));
15033 /* Check for mixed types and values. */
15034 if ((TREE_CODE (parm) == TEMPLATE_TYPE_PARM
15035 && TREE_CODE (tparm) != TYPE_DECL)
15036 || (TREE_CODE (parm) == TEMPLATE_TEMPLATE_PARM
15037 && TREE_CODE (tparm) != TEMPLATE_DECL))
15040 if (TREE_CODE (parm) == BOUND_TEMPLATE_TEMPLATE_PARM)
15042 /* ARG must be constructed from a template class or a template
15043 template parameter. */
15044 if (TREE_CODE (arg) != BOUND_TEMPLATE_TEMPLATE_PARM
15045 && !CLASSTYPE_SPECIALIZATION_OF_PRIMARY_TEMPLATE_P (arg))
15049 tree parmvec = TYPE_TI_ARGS (parm);
15050 tree argvec = INNERMOST_TEMPLATE_ARGS (TYPE_TI_ARGS (arg));
15051 tree full_argvec = add_to_template_args (targs, argvec);
15053 = DECL_INNERMOST_TEMPLATE_PARMS
15054 (TEMPLATE_TEMPLATE_PARM_TEMPLATE_DECL (parm));
15056 int parm_variadic_p = 0;
15058 /* The resolution to DR150 makes clear that default
15059 arguments for an N-argument may not be used to bind T
15060 to a template template parameter with fewer than N
15061 parameters. It is not safe to permit the binding of
15062 default arguments as an extension, as that may change
15063 the meaning of a conforming program. Consider:
15065 struct Dense { static const unsigned int dim = 1; };
15067 template <template <typename> class View,
15069 void operator+(float, View<Block> const&);
15071 template <typename Block,
15072 unsigned int Dim = Block::dim>
15073 struct Lvalue_proxy { operator float() const; };
15077 Lvalue_proxy<Dense> p;
15082 Here, if Lvalue_proxy is permitted to bind to View, then
15083 the global operator+ will be used; if they are not, the
15084 Lvalue_proxy will be converted to float. */
15085 if (coerce_template_parms (parm_parms,
15087 TYPE_TI_TEMPLATE (parm),
15089 /*require_all_args=*/true,
15090 /*use_default_args=*/false)
15091 == error_mark_node)
15094 /* Deduce arguments T, i from TT<T> or TT<i>.
15095 We check each element of PARMVEC and ARGVEC individually
15096 rather than the whole TREE_VEC since they can have
15097 different number of elements. */
15099 parmvec = expand_template_argument_pack (parmvec);
15100 argvec = expand_template_argument_pack (argvec);
15102 len = TREE_VEC_LENGTH (parmvec);
15104 /* Check if the parameters end in a pack, making them
15107 && PACK_EXPANSION_P (TREE_VEC_ELT (parmvec, len - 1)))
15108 parm_variadic_p = 1;
15110 if (TREE_VEC_LENGTH (argvec) < len - parm_variadic_p)
15113 for (i = 0; i < len - parm_variadic_p; ++i)
15115 if (unify (tparms, targs,
15116 TREE_VEC_ELT (parmvec, i),
15117 TREE_VEC_ELT (argvec, i),
15122 if (parm_variadic_p
15123 && unify_pack_expansion (tparms, targs,
15126 /*call_args_p=*/false,
15130 arg = TYPE_TI_TEMPLATE (arg);
15132 /* Fall through to deduce template name. */
15135 if (TREE_CODE (parm) == TEMPLATE_TEMPLATE_PARM
15136 || TREE_CODE (parm) == BOUND_TEMPLATE_TEMPLATE_PARM)
15138 /* Deduce template name TT from TT, TT<>, TT<T> and TT<i>. */
15140 /* Simple cases: Value already set, does match or doesn't. */
15141 if (targ != NULL_TREE && template_args_equal (targ, arg))
15148 /* If PARM is `const T' and ARG is only `int', we don't have
15149 a match unless we are allowing additional qualification.
15150 If ARG is `const int' and PARM is just `T' that's OK;
15151 that binds `const int' to `T'. */
15152 if (!check_cv_quals_for_unify (strict_in | UNIFY_ALLOW_LESS_CV_QUAL,
15156 /* Consider the case where ARG is `const volatile int' and
15157 PARM is `const T'. Then, T should be `volatile int'. */
15158 arg = cp_build_qualified_type_real
15159 (arg, cp_type_quals (arg) & ~cp_type_quals (parm), tf_none);
15160 if (arg == error_mark_node)
15163 /* Simple cases: Value already set, does match or doesn't. */
15164 if (targ != NULL_TREE && same_type_p (targ, arg))
15169 /* Make sure that ARG is not a variable-sized array. (Note
15170 that were talking about variable-sized arrays (like
15171 `int[n]'), rather than arrays of unknown size (like
15172 `int[]').) We'll get very confused by such a type since
15173 the bound of the array will not be computable in an
15174 instantiation. Besides, such types are not allowed in
15175 ISO C++, so we can do as we please here. */
15176 if (variably_modified_type_p (arg, NULL_TREE))
15179 /* Strip typedefs as in convert_template_argument. */
15180 arg = strip_typedefs (arg);
15183 /* If ARG is a parameter pack or an expansion, we cannot unify
15184 against it unless PARM is also a parameter pack. */
15185 if ((template_parameter_pack_p (arg) || PACK_EXPANSION_P (arg))
15186 && !template_parameter_pack_p (parm))
15189 /* If the argument deduction results is a METHOD_TYPE,
15190 then there is a problem.
15191 METHOD_TYPE doesn't map to any real C++ type the result of
15192 the deduction can not be of that type. */
15193 if (TREE_CODE (arg) == METHOD_TYPE)
15196 TREE_VEC_ELT (INNERMOST_TEMPLATE_ARGS (targs), idx) = arg;
15199 case TEMPLATE_PARM_INDEX:
15200 tparm = TREE_VALUE (TREE_VEC_ELT (tparms, 0));
15201 if (tparm == error_mark_node)
15204 if (TEMPLATE_PARM_LEVEL (parm)
15205 != template_decl_level (tparm))
15206 /* The PARM is not one we're trying to unify. Just check
15207 to see if it matches ARG. */
15208 return !(TREE_CODE (arg) == TREE_CODE (parm)
15209 && cp_tree_equal (parm, arg));
15211 idx = TEMPLATE_PARM_IDX (parm);
15212 targ = TREE_VEC_ELT (INNERMOST_TEMPLATE_ARGS (targs), idx);
15215 return !cp_tree_equal (targ, arg);
15217 /* [temp.deduct.type] If, in the declaration of a function template
15218 with a non-type template-parameter, the non-type
15219 template-parameter is used in an expression in the function
15220 parameter-list and, if the corresponding template-argument is
15221 deduced, the template-argument type shall match the type of the
15222 template-parameter exactly, except that a template-argument
15223 deduced from an array bound may be of any integral type.
15224 The non-type parameter might use already deduced type parameters. */
15225 tparm = tsubst (TREE_TYPE (parm), targs, 0, NULL_TREE);
15226 if (!TREE_TYPE (arg))
15227 /* Template-parameter dependent expression. Just accept it for now.
15228 It will later be processed in convert_template_argument. */
15230 else if (same_type_p (TREE_TYPE (arg), tparm))
15232 else if ((strict & UNIFY_ALLOW_INTEGER)
15233 && (TREE_CODE (tparm) == INTEGER_TYPE
15234 || TREE_CODE (tparm) == BOOLEAN_TYPE))
15235 /* Convert the ARG to the type of PARM; the deduced non-type
15236 template argument must exactly match the types of the
15237 corresponding parameter. */
15238 arg = fold (build_nop (tparm, arg));
15239 else if (uses_template_parms (tparm))
15240 /* We haven't deduced the type of this parameter yet. Try again
15246 /* If ARG is a parameter pack or an expansion, we cannot unify
15247 against it unless PARM is also a parameter pack. */
15248 if ((template_parameter_pack_p (arg) || PACK_EXPANSION_P (arg))
15249 && !TEMPLATE_PARM_PARAMETER_PACK (parm))
15252 TREE_VEC_ELT (INNERMOST_TEMPLATE_ARGS (targs), idx) = arg;
15257 /* A pointer-to-member constant can be unified only with
15258 another constant. */
15259 if (TREE_CODE (arg) != PTRMEM_CST)
15262 /* Just unify the class member. It would be useless (and possibly
15263 wrong, depending on the strict flags) to unify also
15264 PTRMEM_CST_CLASS, because we want to be sure that both parm and
15265 arg refer to the same variable, even if through different
15266 classes. For instance:
15268 struct A { int x; };
15271 Unification of &A::x and &B::x must succeed. */
15272 return unify (tparms, targs, PTRMEM_CST_MEMBER (parm),
15273 PTRMEM_CST_MEMBER (arg), strict);
15278 if (TREE_CODE (arg) != POINTER_TYPE)
15281 /* [temp.deduct.call]
15283 A can be another pointer or pointer to member type that can
15284 be converted to the deduced A via a qualification
15285 conversion (_conv.qual_).
15287 We pass down STRICT here rather than UNIFY_ALLOW_NONE.
15288 This will allow for additional cv-qualification of the
15289 pointed-to types if appropriate. */
15291 if (TREE_CODE (TREE_TYPE (arg)) == RECORD_TYPE)
15292 /* The derived-to-base conversion only persists through one
15293 level of pointers. */
15294 strict |= (strict_in & UNIFY_ALLOW_DERIVED);
15296 return unify (tparms, targs, TREE_TYPE (parm),
15297 TREE_TYPE (arg), strict);
15300 case REFERENCE_TYPE:
15301 if (TREE_CODE (arg) != REFERENCE_TYPE)
15303 return unify (tparms, targs, TREE_TYPE (parm), TREE_TYPE (arg),
15304 strict & UNIFY_ALLOW_MORE_CV_QUAL);
15307 if (TREE_CODE (arg) != ARRAY_TYPE)
15309 if ((TYPE_DOMAIN (parm) == NULL_TREE)
15310 != (TYPE_DOMAIN (arg) == NULL_TREE))
15312 if (TYPE_DOMAIN (parm) != NULL_TREE)
15319 /* Our representation of array types uses "N - 1" as the
15320 TYPE_MAX_VALUE for an array with "N" elements, if "N" is
15321 not an integer constant. We cannot unify arbitrarily
15322 complex expressions, so we eliminate the MINUS_EXPRs
15324 parm_max = TYPE_MAX_VALUE (TYPE_DOMAIN (parm));
15325 parm_cst = TREE_CODE (parm_max) == INTEGER_CST;
15328 gcc_assert (TREE_CODE (parm_max) == MINUS_EXPR);
15329 parm_max = TREE_OPERAND (parm_max, 0);
15331 arg_max = TYPE_MAX_VALUE (TYPE_DOMAIN (arg));
15332 arg_cst = TREE_CODE (arg_max) == INTEGER_CST;
15335 /* The ARG_MAX may not be a simple MINUS_EXPR, if we are
15336 trying to unify the type of a variable with the type
15337 of a template parameter. For example:
15339 template <unsigned int N>
15340 void f (char (&) [N]);
15347 Here, the type of the ARG will be "int [g(i)]", and
15348 may be a SAVE_EXPR, etc. */
15349 if (TREE_CODE (arg_max) != MINUS_EXPR)
15351 arg_max = TREE_OPERAND (arg_max, 0);
15354 /* If only one of the bounds used a MINUS_EXPR, compensate
15355 by adding one to the other bound. */
15356 if (parm_cst && !arg_cst)
15357 parm_max = fold_build2_loc (input_location, PLUS_EXPR,
15361 else if (arg_cst && !parm_cst)
15362 arg_max = fold_build2_loc (input_location, PLUS_EXPR,
15367 if (unify (tparms, targs, parm_max, arg_max, UNIFY_ALLOW_INTEGER))
15370 return unify (tparms, targs, TREE_TYPE (parm), TREE_TYPE (arg),
15371 strict & UNIFY_ALLOW_MORE_CV_QUAL);
15378 case ENUMERAL_TYPE:
15380 if (TREE_CODE (arg) != TREE_CODE (parm))
15383 /* We have already checked cv-qualification at the top of the
15385 if (!same_type_ignoring_top_level_qualifiers_p (arg, parm))
15388 /* As far as unification is concerned, this wins. Later checks
15389 will invalidate it if necessary. */
15392 /* Types INTEGER_CST and MINUS_EXPR can come from array bounds. */
15393 /* Type INTEGER_CST can come from ordinary constant template args. */
15395 while (TREE_CODE (arg) == NOP_EXPR)
15396 arg = TREE_OPERAND (arg, 0);
15398 if (TREE_CODE (arg) != INTEGER_CST)
15400 return !tree_int_cst_equal (parm, arg);
15405 if (TREE_CODE (arg) != TREE_VEC)
15407 if (TREE_VEC_LENGTH (parm) != TREE_VEC_LENGTH (arg))
15409 for (i = 0; i < TREE_VEC_LENGTH (parm); ++i)
15410 if (unify (tparms, targs,
15411 TREE_VEC_ELT (parm, i), TREE_VEC_ELT (arg, i),
15419 if (TREE_CODE (arg) != TREE_CODE (parm))
15422 if (TYPE_PTRMEMFUNC_P (parm))
15424 if (!TYPE_PTRMEMFUNC_P (arg))
15427 return unify (tparms, targs,
15428 TYPE_PTRMEMFUNC_FN_TYPE (parm),
15429 TYPE_PTRMEMFUNC_FN_TYPE (arg),
15433 if (CLASSTYPE_TEMPLATE_INFO (parm))
15435 tree t = NULL_TREE;
15437 if (strict_in & UNIFY_ALLOW_DERIVED)
15439 /* First, we try to unify the PARM and ARG directly. */
15440 t = try_class_unification (tparms, targs,
15445 /* Fallback to the special case allowed in
15446 [temp.deduct.call]:
15448 If P is a class, and P has the form
15449 template-id, then A can be a derived class of
15450 the deduced A. Likewise, if P is a pointer to
15451 a class of the form template-id, A can be a
15452 pointer to a derived class pointed to by the
15454 t = get_template_base (tparms, targs, parm, arg);
15460 else if (CLASSTYPE_TEMPLATE_INFO (arg)
15461 && (CLASSTYPE_TI_TEMPLATE (parm)
15462 == CLASSTYPE_TI_TEMPLATE (arg)))
15463 /* Perhaps PARM is something like S<U> and ARG is S<int>.
15464 Then, we should unify `int' and `U'. */
15467 /* There's no chance of unification succeeding. */
15470 return unify (tparms, targs, CLASSTYPE_TI_ARGS (parm),
15471 CLASSTYPE_TI_ARGS (t), UNIFY_ALLOW_NONE);
15473 else if (!same_type_ignoring_top_level_qualifiers_p (parm, arg))
15478 case FUNCTION_TYPE:
15480 unsigned int nargs;
15485 if (TREE_CODE (arg) != TREE_CODE (parm))
15488 /* CV qualifications for methods can never be deduced, they must
15489 match exactly. We need to check them explicitly here,
15490 because type_unification_real treats them as any other
15491 cv-qualified parameter. */
15492 if (TREE_CODE (parm) == METHOD_TYPE
15493 && (!check_cv_quals_for_unify
15495 TREE_TYPE (TREE_VALUE (TYPE_ARG_TYPES (arg))),
15496 TREE_TYPE (TREE_VALUE (TYPE_ARG_TYPES (parm))))))
15499 if (unify (tparms, targs, TREE_TYPE (parm),
15500 TREE_TYPE (arg), UNIFY_ALLOW_NONE))
15503 nargs = list_length (TYPE_ARG_TYPES (arg));
15504 args = XALLOCAVEC (tree, nargs);
15505 for (a = TYPE_ARG_TYPES (arg), i = 0;
15506 a != NULL_TREE && a != void_list_node;
15507 a = TREE_CHAIN (a), ++i)
15508 args[i] = TREE_VALUE (a);
15511 return type_unification_real (tparms, targs, TYPE_ARG_TYPES (parm),
15512 args, nargs, 1, DEDUCE_EXACT,
15517 /* Unify a pointer to member with a pointer to member function, which
15518 deduces the type of the member as a function type. */
15519 if (TYPE_PTRMEMFUNC_P (arg))
15524 /* Check top-level cv qualifiers */
15525 if (!check_cv_quals_for_unify (UNIFY_ALLOW_NONE, arg, parm))
15528 if (unify (tparms, targs, TYPE_OFFSET_BASETYPE (parm),
15529 TYPE_PTRMEMFUNC_OBJECT_TYPE (arg), UNIFY_ALLOW_NONE))
15532 /* Determine the type of the function we are unifying against. */
15533 method_type = TREE_TYPE (TYPE_PTRMEMFUNC_FN_TYPE (arg));
15535 build_function_type (TREE_TYPE (method_type),
15536 TREE_CHAIN (TYPE_ARG_TYPES (method_type)));
15538 /* Extract the cv-qualifiers of the member function from the
15539 implicit object parameter and place them on the function
15540 type to be restored later. */
15541 fntype = apply_memfn_quals (fntype, type_memfn_quals (method_type));
15542 return unify (tparms, targs, TREE_TYPE (parm), fntype, strict);
15545 if (TREE_CODE (arg) != OFFSET_TYPE)
15547 if (unify (tparms, targs, TYPE_OFFSET_BASETYPE (parm),
15548 TYPE_OFFSET_BASETYPE (arg), UNIFY_ALLOW_NONE))
15550 return unify (tparms, targs, TREE_TYPE (parm), TREE_TYPE (arg),
15554 if (DECL_TEMPLATE_PARM_P (parm))
15555 return unify (tparms, targs, DECL_INITIAL (parm), arg, strict);
15556 if (arg != integral_constant_value (parm))
15561 case TEMPLATE_DECL:
15562 /* Matched cases are handled by the ARG == PARM test above. */
15566 /* A non-type template parameter that is a variable should be a
15567 an integral constant, in which case, it whould have been
15568 folded into its (constant) value. So we should not be getting
15569 a variable here. */
15570 gcc_unreachable ();
15572 case TYPE_ARGUMENT_PACK:
15573 case NONTYPE_ARGUMENT_PACK:
15575 tree packed_parms = ARGUMENT_PACK_ARGS (parm);
15576 tree packed_args = ARGUMENT_PACK_ARGS (arg);
15577 int i, len = TREE_VEC_LENGTH (packed_parms);
15578 int argslen = TREE_VEC_LENGTH (packed_args);
15579 int parm_variadic_p = 0;
15581 for (i = 0; i < len; ++i)
15583 if (PACK_EXPANSION_P (TREE_VEC_ELT (packed_parms, i)))
15586 /* We can unify against something with a trailing
15588 parm_variadic_p = 1;
15590 /* Since there is something following the pack
15591 expansion, we cannot unify this template argument
15598 /* If we don't have enough arguments to satisfy the parameters
15599 (not counting the pack expression at the end), or we have
15600 too many arguments for a parameter list that doesn't end in
15601 a pack expression, we can't unify. */
15602 if (argslen < (len - parm_variadic_p)
15603 || (argslen > len && !parm_variadic_p))
15606 /* Unify all of the parameters that precede the (optional)
15607 pack expression. */
15608 for (i = 0; i < len - parm_variadic_p; ++i)
15610 if (unify (tparms, targs, TREE_VEC_ELT (packed_parms, i),
15611 TREE_VEC_ELT (packed_args, i), strict))
15615 if (parm_variadic_p)
15616 return unify_pack_expansion (tparms, targs,
15617 packed_parms, packed_args,
15618 strict, /*call_args_p=*/false,
15626 case DECLTYPE_TYPE:
15627 /* Cannot deduce anything from TYPEOF_TYPE or DECLTYPE_TYPE
15632 /* Unification fails if we hit an error node. */
15636 gcc_assert (EXPR_P (parm));
15638 /* We must be looking at an expression. This can happen with
15642 void foo(S<I>, S<I + 2>);
15644 This is a "nondeduced context":
15648 The nondeduced contexts are:
15650 --A type that is a template-id in which one or more of
15651 the template-arguments is an expression that references
15652 a template-parameter.
15654 In these cases, we assume deduction succeeded, but don't
15655 actually infer any unifications. */
15657 if (!uses_template_parms (parm)
15658 && !template_args_equal (parm, arg))
15665 /* Note that DECL can be defined in this translation unit, if
15669 mark_definable (tree decl)
15672 DECL_NOT_REALLY_EXTERN (decl) = 1;
15673 FOR_EACH_CLONE (clone, decl)
15674 DECL_NOT_REALLY_EXTERN (clone) = 1;
15677 /* Called if RESULT is explicitly instantiated, or is a member of an
15678 explicitly instantiated class. */
15681 mark_decl_instantiated (tree result, int extern_p)
15683 SET_DECL_EXPLICIT_INSTANTIATION (result);
15685 /* If this entity has already been written out, it's too late to
15686 make any modifications. */
15687 if (TREE_ASM_WRITTEN (result))
15690 if (TREE_CODE (result) != FUNCTION_DECL)
15691 /* The TREE_PUBLIC flag for function declarations will have been
15692 set correctly by tsubst. */
15693 TREE_PUBLIC (result) = 1;
15695 /* This might have been set by an earlier implicit instantiation. */
15696 DECL_COMDAT (result) = 0;
15699 DECL_NOT_REALLY_EXTERN (result) = 0;
15702 mark_definable (result);
15703 /* Always make artificials weak. */
15704 if (DECL_ARTIFICIAL (result) && flag_weak)
15705 comdat_linkage (result);
15706 /* For WIN32 we also want to put explicit instantiations in
15707 linkonce sections. */
15708 else if (TREE_PUBLIC (result))
15709 maybe_make_one_only (result);
15712 /* If EXTERN_P, then this function will not be emitted -- unless
15713 followed by an explicit instantiation, at which point its linkage
15714 will be adjusted. If !EXTERN_P, then this function will be
15715 emitted here. In neither circumstance do we want
15716 import_export_decl to adjust the linkage. */
15717 DECL_INTERFACE_KNOWN (result) = 1;
15720 /* Subroutine of more_specialized_fn: check whether TARGS is missing any
15721 important template arguments. If any are missing, we check whether
15722 they're important by using error_mark_node for substituting into any
15723 args that were used for partial ordering (the ones between ARGS and END)
15724 and seeing if it bubbles up. */
15727 check_undeduced_parms (tree targs, tree args, tree end)
15729 bool found = false;
15731 for (i = TREE_VEC_LENGTH (targs) - 1; i >= 0; --i)
15732 if (TREE_VEC_ELT (targs, i) == NULL_TREE)
15735 TREE_VEC_ELT (targs, i) = error_mark_node;
15739 for (; args != end; args = TREE_CHAIN (args))
15741 tree substed = tsubst (TREE_VALUE (args), targs, tf_none, NULL_TREE);
15742 if (substed == error_mark_node)
15749 /* Given two function templates PAT1 and PAT2, return:
15751 1 if PAT1 is more specialized than PAT2 as described in [temp.func.order].
15752 -1 if PAT2 is more specialized than PAT1.
15753 0 if neither is more specialized.
15755 LEN indicates the number of parameters we should consider
15756 (defaulted parameters should not be considered).
15758 The 1998 std underspecified function template partial ordering, and
15759 DR214 addresses the issue. We take pairs of arguments, one from
15760 each of the templates, and deduce them against each other. One of
15761 the templates will be more specialized if all the *other*
15762 template's arguments deduce against its arguments and at least one
15763 of its arguments *does* *not* deduce against the other template's
15764 corresponding argument. Deduction is done as for class templates.
15765 The arguments used in deduction have reference and top level cv
15766 qualifiers removed. Iff both arguments were originally reference
15767 types *and* deduction succeeds in both directions, the template
15768 with the more cv-qualified argument wins for that pairing (if
15769 neither is more cv-qualified, they both are equal). Unlike regular
15770 deduction, after all the arguments have been deduced in this way,
15771 we do *not* verify the deduced template argument values can be
15772 substituted into non-deduced contexts.
15774 The logic can be a bit confusing here, because we look at deduce1 and
15775 targs1 to see if pat2 is at least as specialized, and vice versa; if we
15776 can find template arguments for pat1 to make arg1 look like arg2, that
15777 means that arg2 is at least as specialized as arg1. */
15780 more_specialized_fn (tree pat1, tree pat2, int len)
15782 tree decl1 = DECL_TEMPLATE_RESULT (pat1);
15783 tree decl2 = DECL_TEMPLATE_RESULT (pat2);
15784 tree targs1 = make_tree_vec (DECL_NTPARMS (pat1));
15785 tree targs2 = make_tree_vec (DECL_NTPARMS (pat2));
15786 tree tparms1 = DECL_INNERMOST_TEMPLATE_PARMS (pat1);
15787 tree tparms2 = DECL_INNERMOST_TEMPLATE_PARMS (pat2);
15788 tree args1 = TYPE_ARG_TYPES (TREE_TYPE (decl1));
15789 tree args2 = TYPE_ARG_TYPES (TREE_TYPE (decl2));
15790 tree origs1, origs2;
15791 bool lose1 = false;
15792 bool lose2 = false;
15794 /* Remove the this parameter from non-static member functions. If
15795 one is a non-static member function and the other is not a static
15796 member function, remove the first parameter from that function
15797 also. This situation occurs for operator functions where we
15798 locate both a member function (with this pointer) and non-member
15799 operator (with explicit first operand). */
15800 if (DECL_NONSTATIC_MEMBER_FUNCTION_P (decl1))
15802 len--; /* LEN is the number of significant arguments for DECL1 */
15803 args1 = TREE_CHAIN (args1);
15804 if (!DECL_STATIC_FUNCTION_P (decl2))
15805 args2 = TREE_CHAIN (args2);
15807 else if (DECL_NONSTATIC_MEMBER_FUNCTION_P (decl2))
15809 args2 = TREE_CHAIN (args2);
15810 if (!DECL_STATIC_FUNCTION_P (decl1))
15813 args1 = TREE_CHAIN (args1);
15817 /* If only one is a conversion operator, they are unordered. */
15818 if (DECL_CONV_FN_P (decl1) != DECL_CONV_FN_P (decl2))
15821 /* Consider the return type for a conversion function */
15822 if (DECL_CONV_FN_P (decl1))
15824 args1 = tree_cons (NULL_TREE, TREE_TYPE (TREE_TYPE (decl1)), args1);
15825 args2 = tree_cons (NULL_TREE, TREE_TYPE (TREE_TYPE (decl2)), args2);
15829 processing_template_decl++;
15835 /* Stop when an ellipsis is seen. */
15836 && args1 != NULL_TREE && args2 != NULL_TREE)
15838 tree arg1 = TREE_VALUE (args1);
15839 tree arg2 = TREE_VALUE (args2);
15840 int deduce1, deduce2;
15844 if (TREE_CODE (arg1) == TYPE_PACK_EXPANSION
15845 && TREE_CODE (arg2) == TYPE_PACK_EXPANSION)
15847 /* When both arguments are pack expansions, we need only
15848 unify the patterns themselves. */
15849 arg1 = PACK_EXPANSION_PATTERN (arg1);
15850 arg2 = PACK_EXPANSION_PATTERN (arg2);
15852 /* This is the last comparison we need to do. */
15856 if (TREE_CODE (arg1) == REFERENCE_TYPE)
15858 arg1 = TREE_TYPE (arg1);
15859 quals1 = cp_type_quals (arg1);
15862 if (TREE_CODE (arg2) == REFERENCE_TYPE)
15864 arg2 = TREE_TYPE (arg2);
15865 quals2 = cp_type_quals (arg2);
15868 if ((quals1 < 0) != (quals2 < 0))
15870 /* Only of the args is a reference, see if we should apply
15871 array/function pointer decay to it. This is not part of
15872 DR214, but is, IMHO, consistent with the deduction rules
15873 for the function call itself, and with our earlier
15874 implementation of the underspecified partial ordering
15875 rules. (nathan). */
15878 switch (TREE_CODE (arg1))
15881 arg1 = TREE_TYPE (arg1);
15883 case FUNCTION_TYPE:
15884 arg1 = build_pointer_type (arg1);
15893 switch (TREE_CODE (arg2))
15896 arg2 = TREE_TYPE (arg2);
15898 case FUNCTION_TYPE:
15899 arg2 = build_pointer_type (arg2);
15908 arg1 = TYPE_MAIN_VARIANT (arg1);
15909 arg2 = TYPE_MAIN_VARIANT (arg2);
15911 if (TREE_CODE (arg1) == TYPE_PACK_EXPANSION)
15913 int i, len2 = list_length (args2);
15914 tree parmvec = make_tree_vec (1);
15915 tree argvec = make_tree_vec (len2);
15918 /* Setup the parameter vector, which contains only ARG1. */
15919 TREE_VEC_ELT (parmvec, 0) = arg1;
15921 /* Setup the argument vector, which contains the remaining
15923 for (i = 0; i < len2; i++, ta = TREE_CHAIN (ta))
15924 TREE_VEC_ELT (argvec, i) = TREE_VALUE (ta);
15926 deduce1 = !unify_pack_expansion (tparms1, targs1, parmvec,
15927 argvec, UNIFY_ALLOW_NONE,
15928 /*call_args_p=*/false,
15931 /* We cannot deduce in the other direction, because ARG1 is
15932 a pack expansion but ARG2 is not. */
15935 else if (TREE_CODE (arg2) == TYPE_PACK_EXPANSION)
15937 int i, len1 = list_length (args1);
15938 tree parmvec = make_tree_vec (1);
15939 tree argvec = make_tree_vec (len1);
15942 /* Setup the parameter vector, which contains only ARG1. */
15943 TREE_VEC_ELT (parmvec, 0) = arg2;
15945 /* Setup the argument vector, which contains the remaining
15947 for (i = 0; i < len1; i++, ta = TREE_CHAIN (ta))
15948 TREE_VEC_ELT (argvec, i) = TREE_VALUE (ta);
15950 deduce2 = !unify_pack_expansion (tparms2, targs2, parmvec,
15951 argvec, UNIFY_ALLOW_NONE,
15952 /*call_args_p=*/false,
15955 /* We cannot deduce in the other direction, because ARG2 is
15956 a pack expansion but ARG1 is not.*/
15962 /* The normal case, where neither argument is a pack
15964 deduce1 = !unify (tparms1, targs1, arg1, arg2, UNIFY_ALLOW_NONE);
15965 deduce2 = !unify (tparms2, targs2, arg2, arg1, UNIFY_ALLOW_NONE);
15968 /* If we couldn't deduce arguments for tparms1 to make arg1 match
15969 arg2, then arg2 is not as specialized as arg1. */
15975 /* "If, for a given type, deduction succeeds in both directions
15976 (i.e., the types are identical after the transformations above)
15977 and if the type from the argument template is more cv-qualified
15978 than the type from the parameter template (as described above)
15979 that type is considered to be more specialized than the other. If
15980 neither type is more cv-qualified than the other then neither type
15981 is more specialized than the other." */
15983 if (deduce1 && deduce2
15984 && quals1 != quals2 && quals1 >= 0 && quals2 >= 0)
15986 if ((quals1 & quals2) == quals2)
15988 if ((quals1 & quals2) == quals1)
15992 if (lose1 && lose2)
15993 /* We've failed to deduce something in either direction.
15994 These must be unordered. */
15997 if (TREE_CODE (arg1) == TYPE_PACK_EXPANSION
15998 || TREE_CODE (arg2) == TYPE_PACK_EXPANSION)
15999 /* We have already processed all of the arguments in our
16000 handing of the pack expansion type. */
16003 args1 = TREE_CHAIN (args1);
16004 args2 = TREE_CHAIN (args2);
16007 /* "In most cases, all template parameters must have values in order for
16008 deduction to succeed, but for partial ordering purposes a template
16009 parameter may remain without a value provided it is not used in the
16010 types being used for partial ordering."
16012 Thus, if we are missing any of the targs1 we need to substitute into
16013 origs1, then pat2 is not as specialized as pat1. This can happen when
16014 there is a nondeduced context. */
16015 if (!lose2 && check_undeduced_parms (targs1, origs1, args1))
16017 if (!lose1 && check_undeduced_parms (targs2, origs2, args2))
16020 processing_template_decl--;
16022 /* All things being equal, if the next argument is a pack expansion
16023 for one function but not for the other, prefer the
16024 non-variadic function. FIXME this is bogus; see c++/41958. */
16026 && args1 && TREE_VALUE (args1)
16027 && args2 && TREE_VALUE (args2))
16029 lose1 = TREE_CODE (TREE_VALUE (args1)) == TYPE_PACK_EXPANSION;
16030 lose2 = TREE_CODE (TREE_VALUE (args2)) == TYPE_PACK_EXPANSION;
16033 if (lose1 == lose2)
16041 /* Determine which of two partial specializations is more specialized.
16043 PAT1 is a TREE_LIST whose TREE_TYPE is the _TYPE node corresponding
16044 to the first partial specialization. The TREE_VALUE is the
16045 innermost set of template parameters for the partial
16046 specialization. PAT2 is similar, but for the second template.
16048 Return 1 if the first partial specialization is more specialized;
16049 -1 if the second is more specialized; 0 if neither is more
16052 See [temp.class.order] for information about determining which of
16053 two templates is more specialized. */
16056 more_specialized_class (tree pat1, tree pat2)
16061 bool any_deductions = false;
16063 tmpl1 = TREE_TYPE (pat1);
16064 tmpl2 = TREE_TYPE (pat2);
16066 /* Just like what happens for functions, if we are ordering between
16067 different class template specializations, we may encounter dependent
16068 types in the arguments, and we need our dependency check functions
16069 to behave correctly. */
16070 ++processing_template_decl;
16071 targs = get_class_bindings (TREE_VALUE (pat1),
16072 CLASSTYPE_TI_ARGS (tmpl1),
16073 CLASSTYPE_TI_ARGS (tmpl2));
16077 any_deductions = true;
16080 targs = get_class_bindings (TREE_VALUE (pat2),
16081 CLASSTYPE_TI_ARGS (tmpl2),
16082 CLASSTYPE_TI_ARGS (tmpl1));
16086 any_deductions = true;
16088 --processing_template_decl;
16090 /* In the case of a tie where at least one of the class templates
16091 has a parameter pack at the end, the template with the most
16092 non-packed parameters wins. */
16095 && (template_args_variadic_p (TREE_PURPOSE (pat1))
16096 || template_args_variadic_p (TREE_PURPOSE (pat2))))
16098 tree args1 = INNERMOST_TEMPLATE_ARGS (TREE_PURPOSE (pat1));
16099 tree args2 = INNERMOST_TEMPLATE_ARGS (TREE_PURPOSE (pat2));
16100 int len1 = TREE_VEC_LENGTH (args1);
16101 int len2 = TREE_VEC_LENGTH (args2);
16103 /* We don't count the pack expansion at the end. */
16104 if (template_args_variadic_p (TREE_PURPOSE (pat1)))
16106 if (template_args_variadic_p (TREE_PURPOSE (pat2)))
16111 else if (len1 < len2)
16118 /* Return the template arguments that will produce the function signature
16119 DECL from the function template FN, with the explicit template
16120 arguments EXPLICIT_ARGS. If CHECK_RETTYPE is true, the return type must
16121 also match. Return NULL_TREE if no satisfactory arguments could be
16125 get_bindings (tree fn, tree decl, tree explicit_args, bool check_rettype)
16127 int ntparms = DECL_NTPARMS (fn);
16128 tree targs = make_tree_vec (ntparms);
16130 tree decl_arg_types;
16132 unsigned int nargs, ix;
16135 /* Substitute the explicit template arguments into the type of DECL.
16136 The call to fn_type_unification will handle substitution into the
16138 decl_type = TREE_TYPE (decl);
16139 if (explicit_args && uses_template_parms (decl_type))
16142 tree converted_args;
16144 if (DECL_TEMPLATE_INFO (decl))
16145 tmpl = DECL_TI_TEMPLATE (decl);
16147 /* We can get here for some invalid specializations. */
16151 = coerce_template_parms (DECL_INNERMOST_TEMPLATE_PARMS (tmpl),
16152 explicit_args, NULL_TREE,
16154 /*require_all_args=*/false,
16155 /*use_default_args=*/false);
16156 if (converted_args == error_mark_node)
16159 decl_type = tsubst (decl_type, converted_args, tf_none, NULL_TREE);
16160 if (decl_type == error_mark_node)
16164 /* Never do unification on the 'this' parameter. */
16165 decl_arg_types = skip_artificial_parms_for (decl,
16166 TYPE_ARG_TYPES (decl_type));
16168 nargs = list_length (decl_arg_types);
16169 args = XALLOCAVEC (tree, nargs);
16170 for (arg = decl_arg_types, ix = 0;
16171 arg != NULL_TREE && arg != void_list_node;
16172 arg = TREE_CHAIN (arg), ++ix)
16173 args[ix] = TREE_VALUE (arg);
16175 if (fn_type_unification (fn, explicit_args, targs,
16177 (check_rettype || DECL_CONV_FN_P (fn)
16178 ? TREE_TYPE (decl_type) : NULL_TREE),
16179 DEDUCE_EXACT, LOOKUP_NORMAL))
16185 /* Return the innermost template arguments that, when applied to a
16186 template specialization whose innermost template parameters are
16187 TPARMS, and whose specialization arguments are SPEC_ARGS, yield the
16190 For example, suppose we have:
16192 template <class T, class U> struct S {};
16193 template <class T> struct S<T*, int> {};
16195 Then, suppose we want to get `S<double*, int>'. The TPARMS will be
16196 {T}, the SPEC_ARGS will be {T*, int} and the ARGS will be {double*,
16197 int}. The resulting vector will be {double}, indicating that `T'
16198 is bound to `double'. */
16201 get_class_bindings (tree tparms, tree spec_args, tree args)
16203 int i, ntparms = TREE_VEC_LENGTH (tparms);
16205 tree innermost_deduced_args;
16207 innermost_deduced_args = make_tree_vec (ntparms);
16208 if (TMPL_ARGS_HAVE_MULTIPLE_LEVELS (args))
16210 deduced_args = copy_node (args);
16211 SET_TMPL_ARGS_LEVEL (deduced_args,
16212 TMPL_ARGS_DEPTH (deduced_args),
16213 innermost_deduced_args);
16216 deduced_args = innermost_deduced_args;
16218 if (unify (tparms, deduced_args,
16219 INNERMOST_TEMPLATE_ARGS (spec_args),
16220 INNERMOST_TEMPLATE_ARGS (args),
16224 for (i = 0; i < ntparms; ++i)
16225 if (! TREE_VEC_ELT (innermost_deduced_args, i))
16228 /* Verify that nondeduced template arguments agree with the type
16229 obtained from argument deduction.
16233 struct A { typedef int X; };
16234 template <class T, class U> struct C {};
16235 template <class T> struct C<T, typename T::X> {};
16237 Then with the instantiation `C<A, int>', we can deduce that
16238 `T' is `A' but unify () does not check whether `typename T::X'
16240 spec_args = tsubst (spec_args, deduced_args, tf_none, NULL_TREE);
16241 if (spec_args == error_mark_node
16242 /* We only need to check the innermost arguments; the other
16243 arguments will always agree. */
16244 || !comp_template_args (INNERMOST_TEMPLATE_ARGS (spec_args),
16245 INNERMOST_TEMPLATE_ARGS (args)))
16248 /* Now that we have bindings for all of the template arguments,
16249 ensure that the arguments deduced for the template template
16250 parameters have compatible template parameter lists. See the use
16251 of template_template_parm_bindings_ok_p in fn_type_unification
16252 for more information. */
16253 if (!template_template_parm_bindings_ok_p (tparms, deduced_args))
16256 return deduced_args;
16259 /* TEMPLATES is a TREE_LIST. Each TREE_VALUE is a TEMPLATE_DECL.
16260 Return the TREE_LIST node with the most specialized template, if
16261 any. If there is no most specialized template, the error_mark_node
16264 Note that this function does not look at, or modify, the
16265 TREE_PURPOSE or TREE_TYPE of any of the nodes. Since the node
16266 returned is one of the elements of INSTANTIATIONS, callers may
16267 store information in the TREE_PURPOSE or TREE_TYPE of the nodes,
16268 and retrieve it from the value returned. */
16271 most_specialized_instantiation (tree templates)
16275 ++processing_template_decl;
16278 for (fn = TREE_CHAIN (templates); fn; fn = TREE_CHAIN (fn))
16282 if (get_bindings (TREE_VALUE (champ),
16283 DECL_TEMPLATE_RESULT (TREE_VALUE (fn)),
16284 NULL_TREE, /*check_ret=*/false))
16287 if (get_bindings (TREE_VALUE (fn),
16288 DECL_TEMPLATE_RESULT (TREE_VALUE (champ)),
16289 NULL_TREE, /*check_ret=*/false))
16296 /* Equally specialized, move to next function. If there
16297 is no next function, nothing's most specialized. */
16298 fn = TREE_CHAIN (fn);
16306 /* Now verify that champ is better than everything earlier in the
16307 instantiation list. */
16308 for (fn = templates; fn != champ; fn = TREE_CHAIN (fn))
16309 if (get_bindings (TREE_VALUE (champ),
16310 DECL_TEMPLATE_RESULT (TREE_VALUE (fn)),
16311 NULL_TREE, /*check_ret=*/false)
16312 || !get_bindings (TREE_VALUE (fn),
16313 DECL_TEMPLATE_RESULT (TREE_VALUE (champ)),
16314 NULL_TREE, /*check_ret=*/false))
16320 processing_template_decl--;
16323 return error_mark_node;
16328 /* If DECL is a specialization of some template, return the most
16329 general such template. Otherwise, returns NULL_TREE.
16331 For example, given:
16333 template <class T> struct S { template <class U> void f(U); };
16335 if TMPL is `template <class U> void S<int>::f(U)' this will return
16336 the full template. This function will not trace past partial
16337 specializations, however. For example, given in addition:
16339 template <class T> struct S<T*> { template <class U> void f(U); };
16341 if TMPL is `template <class U> void S<int*>::f(U)' this will return
16342 `template <class T> template <class U> S<T*>::f(U)'. */
16345 most_general_template (tree decl)
16347 /* If DECL is a FUNCTION_DECL, find the TEMPLATE_DECL of which it is
16348 an immediate specialization. */
16349 if (TREE_CODE (decl) == FUNCTION_DECL)
16351 if (DECL_TEMPLATE_INFO (decl)) {
16352 decl = DECL_TI_TEMPLATE (decl);
16354 /* The DECL_TI_TEMPLATE can be an IDENTIFIER_NODE for a
16355 template friend. */
16356 if (TREE_CODE (decl) != TEMPLATE_DECL)
16362 /* Look for more and more general templates. */
16363 while (DECL_TEMPLATE_INFO (decl))
16365 /* The DECL_TI_TEMPLATE can be an IDENTIFIER_NODE in some cases.
16366 (See cp-tree.h for details.) */
16367 if (TREE_CODE (DECL_TI_TEMPLATE (decl)) != TEMPLATE_DECL)
16370 if (CLASS_TYPE_P (TREE_TYPE (decl))
16371 && CLASSTYPE_TEMPLATE_SPECIALIZATION (TREE_TYPE (decl)))
16374 /* Stop if we run into an explicitly specialized class template. */
16375 if (!DECL_NAMESPACE_SCOPE_P (decl)
16376 && DECL_CONTEXT (decl)
16377 && CLASSTYPE_TEMPLATE_SPECIALIZATION (DECL_CONTEXT (decl)))
16380 decl = DECL_TI_TEMPLATE (decl);
16386 /* Return the most specialized of the class template partial
16387 specializations of TMPL which can produce TYPE, a specialization of
16388 TMPL. The value returned is actually a TREE_LIST; the TREE_TYPE is
16389 a _TYPE node corresponding to the partial specialization, while the
16390 TREE_PURPOSE is the set of template arguments that must be
16391 substituted into the TREE_TYPE in order to generate TYPE.
16393 If the choice of partial specialization is ambiguous, a diagnostic
16394 is issued, and the error_mark_node is returned. If there are no
16395 partial specializations of TMPL matching TYPE, then NULL_TREE is
16399 most_specialized_class (tree type, tree tmpl, tsubst_flags_t complain)
16401 tree list = NULL_TREE;
16407 tree outer_args = NULL_TREE;
16409 tmpl = most_general_template (tmpl);
16410 args = CLASSTYPE_TI_ARGS (type);
16412 /* For determining which partial specialization to use, only the
16413 innermost args are interesting. */
16414 if (TMPL_ARGS_HAVE_MULTIPLE_LEVELS (args))
16416 outer_args = strip_innermost_template_args (args, 1);
16417 args = INNERMOST_TEMPLATE_ARGS (args);
16420 for (t = DECL_TEMPLATE_SPECIALIZATIONS (tmpl); t; t = TREE_CHAIN (t))
16422 tree partial_spec_args;
16424 tree parms = TREE_VALUE (t);
16426 partial_spec_args = CLASSTYPE_TI_ARGS (TREE_TYPE (t));
16428 ++processing_template_decl;
16434 /* Discard the outer levels of args, and then substitute in the
16435 template args from the enclosing class. */
16436 partial_spec_args = INNERMOST_TEMPLATE_ARGS (partial_spec_args);
16437 partial_spec_args = tsubst_template_args
16438 (partial_spec_args, outer_args, tf_none, NULL_TREE);
16440 /* PARMS already refers to just the innermost parms, but the
16441 template parms in partial_spec_args had their levels lowered
16442 by tsubst, so we need to do the same for the parm list. We
16443 can't just tsubst the TREE_VEC itself, as tsubst wants to
16444 treat a TREE_VEC as an argument vector. */
16445 parms = copy_node (parms);
16446 for (i = TREE_VEC_LENGTH (parms) - 1; i >= 0; --i)
16447 TREE_VEC_ELT (parms, i) =
16448 tsubst (TREE_VEC_ELT (parms, i), outer_args, tf_none, NULL_TREE);
16452 partial_spec_args =
16453 coerce_template_parms (DECL_INNERMOST_TEMPLATE_PARMS (tmpl),
16454 add_to_template_args (outer_args,
16455 partial_spec_args),
16457 /*require_all_args=*/true,
16458 /*use_default_args=*/true);
16460 --processing_template_decl;
16462 if (partial_spec_args == error_mark_node)
16463 return error_mark_node;
16465 spec_args = get_class_bindings (parms,
16471 spec_args = add_to_template_args (outer_args, spec_args);
16472 list = tree_cons (spec_args, TREE_VALUE (t), list);
16473 TREE_TYPE (list) = TREE_TYPE (t);
16480 ambiguous_p = false;
16483 t = TREE_CHAIN (t);
16484 for (; t; t = TREE_CHAIN (t))
16486 fate = more_specialized_class (champ, t);
16493 t = TREE_CHAIN (t);
16496 ambiguous_p = true;
16505 for (t = list; t && t != champ; t = TREE_CHAIN (t))
16507 fate = more_specialized_class (champ, t);
16510 ambiguous_p = true;
16518 char *spaces = NULL;
16519 if (!(complain & tf_error))
16520 return error_mark_node;
16521 error ("ambiguous class template instantiation for %q#T", type);
16522 str = ngettext ("candidate is:", "candidates are:", list_length (list));
16523 for (t = list; t; t = TREE_CHAIN (t))
16525 error ("%s %+#T", spaces ? spaces : str, TREE_TYPE (t));
16526 spaces = spaces ? spaces : get_spaces (str);
16529 return error_mark_node;
16535 /* Explicitly instantiate DECL. */
16538 do_decl_instantiation (tree decl, tree storage)
16540 tree result = NULL_TREE;
16543 if (!decl || decl == error_mark_node)
16544 /* An error occurred, for which grokdeclarator has already issued
16545 an appropriate message. */
16547 else if (! DECL_LANG_SPECIFIC (decl))
16549 error ("explicit instantiation of non-template %q#D", decl);
16552 else if (TREE_CODE (decl) == VAR_DECL)
16554 /* There is an asymmetry here in the way VAR_DECLs and
16555 FUNCTION_DECLs are handled by grokdeclarator. In the case of
16556 the latter, the DECL we get back will be marked as a
16557 template instantiation, and the appropriate
16558 DECL_TEMPLATE_INFO will be set up. This does not happen for
16559 VAR_DECLs so we do the lookup here. Probably, grokdeclarator
16560 should handle VAR_DECLs as it currently handles
16562 if (!DECL_CLASS_SCOPE_P (decl))
16564 error ("%qD is not a static data member of a class template", decl);
16567 result = lookup_field (DECL_CONTEXT (decl), DECL_NAME (decl), 0, false);
16568 if (!result || TREE_CODE (result) != VAR_DECL)
16570 error ("no matching template for %qD found", decl);
16573 if (!same_type_p (TREE_TYPE (result), TREE_TYPE (decl)))
16575 error ("type %qT for explicit instantiation %qD does not match "
16576 "declared type %qT", TREE_TYPE (result), decl,
16581 else if (TREE_CODE (decl) != FUNCTION_DECL)
16583 error ("explicit instantiation of %q#D", decl);
16589 /* Check for various error cases. Note that if the explicit
16590 instantiation is valid the RESULT will currently be marked as an
16591 *implicit* instantiation; DECL_EXPLICIT_INSTANTIATION is not set
16592 until we get here. */
16594 if (DECL_TEMPLATE_SPECIALIZATION (result))
16596 /* DR 259 [temp.spec].
16598 Both an explicit instantiation and a declaration of an explicit
16599 specialization shall not appear in a program unless the explicit
16600 instantiation follows a declaration of the explicit specialization.
16602 For a given set of template parameters, if an explicit
16603 instantiation of a template appears after a declaration of an
16604 explicit specialization for that template, the explicit
16605 instantiation has no effect. */
16608 else if (DECL_EXPLICIT_INSTANTIATION (result))
16612 No program shall explicitly instantiate any template more
16615 We check DECL_NOT_REALLY_EXTERN so as not to complain when
16616 the first instantiation was `extern' and the second is not,
16617 and EXTERN_P for the opposite case. */
16618 if (DECL_NOT_REALLY_EXTERN (result) && !extern_p)
16619 permerror (input_location, "duplicate explicit instantiation of %q#D", result);
16620 /* If an "extern" explicit instantiation follows an ordinary
16621 explicit instantiation, the template is instantiated. */
16625 else if (!DECL_IMPLICIT_INSTANTIATION (result))
16627 error ("no matching template for %qD found", result);
16630 else if (!DECL_TEMPLATE_INFO (result))
16632 permerror (input_location, "explicit instantiation of non-template %q#D", result);
16636 if (storage == NULL_TREE)
16638 else if (storage == ridpointers[(int) RID_EXTERN])
16640 if (!in_system_header && (cxx_dialect == cxx98))
16641 pedwarn (input_location, OPT_pedantic,
16642 "ISO C++ 1998 forbids the use of %<extern%> on explicit "
16647 error ("storage class %qD applied to template instantiation", storage);
16649 check_explicit_instantiation_namespace (result);
16650 mark_decl_instantiated (result, extern_p);
16652 instantiate_decl (result, /*defer_ok=*/1,
16653 /*expl_inst_class_mem_p=*/false);
16657 mark_class_instantiated (tree t, int extern_p)
16659 SET_CLASSTYPE_EXPLICIT_INSTANTIATION (t);
16660 SET_CLASSTYPE_INTERFACE_KNOWN (t);
16661 CLASSTYPE_INTERFACE_ONLY (t) = extern_p;
16662 TYPE_DECL_SUPPRESS_DEBUG (TYPE_NAME (t)) = extern_p;
16665 CLASSTYPE_DEBUG_REQUESTED (t) = 1;
16666 rest_of_type_compilation (t, 1);
16670 /* Called from do_type_instantiation through binding_table_foreach to
16671 do recursive instantiation for the type bound in ENTRY. */
16673 bt_instantiate_type_proc (binding_entry entry, void *data)
16675 tree storage = *(tree *) data;
16677 if (MAYBE_CLASS_TYPE_P (entry->type)
16678 && !uses_template_parms (CLASSTYPE_TI_ARGS (entry->type)))
16679 do_type_instantiation (TYPE_MAIN_DECL (entry->type), storage, 0);
16682 /* Called from do_type_instantiation to instantiate a member
16683 (a member function or a static member variable) of an
16684 explicitly instantiated class template. */
16686 instantiate_class_member (tree decl, int extern_p)
16688 mark_decl_instantiated (decl, extern_p);
16690 instantiate_decl (decl, /*defer_ok=*/1,
16691 /*expl_inst_class_mem_p=*/true);
16694 /* Perform an explicit instantiation of template class T. STORAGE, if
16695 non-null, is the RID for extern, inline or static. COMPLAIN is
16696 nonzero if this is called from the parser, zero if called recursively,
16697 since the standard is unclear (as detailed below). */
16700 do_type_instantiation (tree t, tree storage, tsubst_flags_t complain)
16705 int previous_instantiation_extern_p = 0;
16707 if (TREE_CODE (t) == TYPE_DECL)
16710 if (! CLASS_TYPE_P (t) || ! CLASSTYPE_TEMPLATE_INFO (t))
16712 error ("explicit instantiation of non-template type %qT", t);
16718 if (!COMPLETE_TYPE_P (t))
16720 if (complain & tf_error)
16721 error ("explicit instantiation of %q#T before definition of template",
16726 if (storage != NULL_TREE)
16728 if (!in_system_header)
16730 if (storage == ridpointers[(int) RID_EXTERN])
16732 if (cxx_dialect == cxx98)
16733 pedwarn (input_location, OPT_pedantic,
16734 "ISO C++ 1998 forbids the use of %<extern%> on "
16735 "explicit instantiations");
16738 pedwarn (input_location, OPT_pedantic,
16739 "ISO C++ forbids the use of %qE"
16740 " on explicit instantiations", storage);
16743 if (storage == ridpointers[(int) RID_INLINE])
16745 else if (storage == ridpointers[(int) RID_EXTERN])
16747 else if (storage == ridpointers[(int) RID_STATIC])
16751 error ("storage class %qD applied to template instantiation",
16757 if (CLASSTYPE_TEMPLATE_SPECIALIZATION (t))
16759 /* DR 259 [temp.spec].
16761 Both an explicit instantiation and a declaration of an explicit
16762 specialization shall not appear in a program unless the explicit
16763 instantiation follows a declaration of the explicit specialization.
16765 For a given set of template parameters, if an explicit
16766 instantiation of a template appears after a declaration of an
16767 explicit specialization for that template, the explicit
16768 instantiation has no effect. */
16771 else if (CLASSTYPE_EXPLICIT_INSTANTIATION (t))
16775 No program shall explicitly instantiate any template more
16778 If PREVIOUS_INSTANTIATION_EXTERN_P, then the first explicit
16779 instantiation was `extern'. If EXTERN_P then the second is.
16780 These cases are OK. */
16781 previous_instantiation_extern_p = CLASSTYPE_INTERFACE_ONLY (t);
16783 if (!previous_instantiation_extern_p && !extern_p
16784 && (complain & tf_error))
16785 permerror (input_location, "duplicate explicit instantiation of %q#T", t);
16787 /* If we've already instantiated the template, just return now. */
16788 if (!CLASSTYPE_INTERFACE_ONLY (t))
16792 check_explicit_instantiation_namespace (TYPE_NAME (t));
16793 mark_class_instantiated (t, extern_p);
16801 /* In contrast to implicit instantiation, where only the
16802 declarations, and not the definitions, of members are
16803 instantiated, we have here:
16807 The explicit instantiation of a class template specialization
16808 implies the instantiation of all of its members not
16809 previously explicitly specialized in the translation unit
16810 containing the explicit instantiation.
16812 Of course, we can't instantiate member template classes, since
16813 we don't have any arguments for them. Note that the standard
16814 is unclear on whether the instantiation of the members are
16815 *explicit* instantiations or not. However, the most natural
16816 interpretation is that it should be an explicit instantiation. */
16819 for (tmp = TYPE_METHODS (t); tmp; tmp = DECL_CHAIN (tmp))
16820 if (TREE_CODE (tmp) == FUNCTION_DECL
16821 && DECL_TEMPLATE_INSTANTIATION (tmp))
16822 instantiate_class_member (tmp, extern_p);
16824 for (tmp = TYPE_FIELDS (t); tmp; tmp = DECL_CHAIN (tmp))
16825 if (TREE_CODE (tmp) == VAR_DECL && DECL_TEMPLATE_INSTANTIATION (tmp))
16826 instantiate_class_member (tmp, extern_p);
16828 if (CLASSTYPE_NESTED_UTDS (t))
16829 binding_table_foreach (CLASSTYPE_NESTED_UTDS (t),
16830 bt_instantiate_type_proc, &storage);
16834 /* Given a function DECL, which is a specialization of TMPL, modify
16835 DECL to be a re-instantiation of TMPL with the same template
16836 arguments. TMPL should be the template into which tsubst'ing
16837 should occur for DECL, not the most general template.
16839 One reason for doing this is a scenario like this:
16842 void f(const T&, int i);
16844 void g() { f(3, 7); }
16847 void f(const T& t, const int i) { }
16849 Note that when the template is first instantiated, with
16850 instantiate_template, the resulting DECL will have no name for the
16851 first parameter, and the wrong type for the second. So, when we go
16852 to instantiate the DECL, we regenerate it. */
16855 regenerate_decl_from_template (tree decl, tree tmpl)
16857 /* The arguments used to instantiate DECL, from the most general
16862 args = DECL_TI_ARGS (decl);
16863 code_pattern = DECL_TEMPLATE_RESULT (tmpl);
16865 /* Make sure that we can see identifiers, and compute access
16867 push_access_scope (decl);
16869 if (TREE_CODE (decl) == FUNCTION_DECL)
16877 args_depth = TMPL_ARGS_DEPTH (args);
16878 parms_depth = TMPL_PARMS_DEPTH (DECL_TEMPLATE_PARMS (tmpl));
16879 if (args_depth > parms_depth)
16880 args = get_innermost_template_args (args, parms_depth);
16882 specs = tsubst_exception_specification (TREE_TYPE (code_pattern),
16883 args, tf_error, NULL_TREE);
16885 TREE_TYPE (decl) = build_exception_variant (TREE_TYPE (decl),
16888 /* Merge parameter declarations. */
16889 decl_parm = skip_artificial_parms_for (decl,
16890 DECL_ARGUMENTS (decl));
16892 = skip_artificial_parms_for (code_pattern,
16893 DECL_ARGUMENTS (code_pattern));
16894 while (decl_parm && !FUNCTION_PARAMETER_PACK_P (pattern_parm))
16899 if (DECL_NAME (decl_parm) != DECL_NAME (pattern_parm))
16900 DECL_NAME (decl_parm) = DECL_NAME (pattern_parm);
16901 parm_type = tsubst (TREE_TYPE (pattern_parm), args, tf_error,
16903 parm_type = type_decays_to (parm_type);
16904 if (!same_type_p (TREE_TYPE (decl_parm), parm_type))
16905 TREE_TYPE (decl_parm) = parm_type;
16906 attributes = DECL_ATTRIBUTES (pattern_parm);
16907 if (DECL_ATTRIBUTES (decl_parm) != attributes)
16909 DECL_ATTRIBUTES (decl_parm) = attributes;
16910 cplus_decl_attributes (&decl_parm, attributes, /*flags=*/0);
16912 decl_parm = DECL_CHAIN (decl_parm);
16913 pattern_parm = DECL_CHAIN (pattern_parm);
16915 /* Merge any parameters that match with the function parameter
16917 if (pattern_parm && FUNCTION_PARAMETER_PACK_P (pattern_parm))
16920 tree expanded_types;
16921 /* Expand the TYPE_PACK_EXPANSION that provides the types for
16922 the parameters in this function parameter pack. */
16923 expanded_types = tsubst_pack_expansion (TREE_TYPE (pattern_parm),
16924 args, tf_error, NULL_TREE);
16925 len = TREE_VEC_LENGTH (expanded_types);
16926 for (i = 0; i < len; i++)
16931 if (DECL_NAME (decl_parm) != DECL_NAME (pattern_parm))
16932 /* Rename the parameter to include the index. */
16933 DECL_NAME (decl_parm) =
16934 make_ith_pack_parameter_name (DECL_NAME (pattern_parm), i);
16935 parm_type = TREE_VEC_ELT (expanded_types, i);
16936 parm_type = type_decays_to (parm_type);
16937 if (!same_type_p (TREE_TYPE (decl_parm), parm_type))
16938 TREE_TYPE (decl_parm) = parm_type;
16939 attributes = DECL_ATTRIBUTES (pattern_parm);
16940 if (DECL_ATTRIBUTES (decl_parm) != attributes)
16942 DECL_ATTRIBUTES (decl_parm) = attributes;
16943 cplus_decl_attributes (&decl_parm, attributes, /*flags=*/0);
16945 decl_parm = DECL_CHAIN (decl_parm);
16948 /* Merge additional specifiers from the CODE_PATTERN. */
16949 if (DECL_DECLARED_INLINE_P (code_pattern)
16950 && !DECL_DECLARED_INLINE_P (decl))
16951 DECL_DECLARED_INLINE_P (decl) = 1;
16953 else if (TREE_CODE (decl) == VAR_DECL)
16955 DECL_INITIAL (decl) =
16956 tsubst_expr (DECL_INITIAL (code_pattern), args,
16957 tf_error, DECL_TI_TEMPLATE (decl),
16958 /*integral_constant_expression_p=*/false);
16959 if (VAR_HAD_UNKNOWN_BOUND (decl))
16960 TREE_TYPE (decl) = tsubst (TREE_TYPE (code_pattern), args,
16961 tf_error, DECL_TI_TEMPLATE (decl));
16964 gcc_unreachable ();
16966 pop_access_scope (decl);
16969 /* Return the TEMPLATE_DECL into which DECL_TI_ARGS(DECL) should be
16970 substituted to get DECL. */
16973 template_for_substitution (tree decl)
16975 tree tmpl = DECL_TI_TEMPLATE (decl);
16977 /* Set TMPL to the template whose DECL_TEMPLATE_RESULT is the pattern
16978 for the instantiation. This is not always the most general
16979 template. Consider, for example:
16982 struct S { template <class U> void f();
16983 template <> void f<int>(); };
16985 and an instantiation of S<double>::f<int>. We want TD to be the
16986 specialization S<T>::f<int>, not the more general S<T>::f<U>. */
16987 while (/* An instantiation cannot have a definition, so we need a
16988 more general template. */
16989 DECL_TEMPLATE_INSTANTIATION (tmpl)
16990 /* We must also deal with friend templates. Given:
16992 template <class T> struct S {
16993 template <class U> friend void f() {};
16996 S<int>::f<U> say, is not an instantiation of S<T>::f<U>,
16997 so far as the language is concerned, but that's still
16998 where we get the pattern for the instantiation from. On
16999 other hand, if the definition comes outside the class, say:
17001 template <class T> struct S {
17002 template <class U> friend void f();
17004 template <class U> friend void f() {}
17006 we don't need to look any further. That's what the check for
17007 DECL_INITIAL is for. */
17008 || (TREE_CODE (decl) == FUNCTION_DECL
17009 && DECL_FRIEND_PSEUDO_TEMPLATE_INSTANTIATION (tmpl)
17010 && !DECL_INITIAL (DECL_TEMPLATE_RESULT (tmpl))))
17012 /* The present template, TD, should not be a definition. If it
17013 were a definition, we should be using it! Note that we
17014 cannot restructure the loop to just keep going until we find
17015 a template with a definition, since that might go too far if
17016 a specialization was declared, but not defined. */
17017 gcc_assert (TREE_CODE (decl) != VAR_DECL
17018 || DECL_IN_AGGR_P (DECL_TEMPLATE_RESULT (tmpl)));
17020 /* Fetch the more general template. */
17021 tmpl = DECL_TI_TEMPLATE (tmpl);
17027 /* Returns true if we need to instantiate this template instance even if we
17028 know we aren't going to emit it.. */
17031 always_instantiate_p (tree decl)
17033 /* We always instantiate inline functions so that we can inline them. An
17034 explicit instantiation declaration prohibits implicit instantiation of
17035 non-inline functions. With high levels of optimization, we would
17036 normally inline non-inline functions -- but we're not allowed to do
17037 that for "extern template" functions. Therefore, we check
17038 DECL_DECLARED_INLINE_P, rather than possibly_inlined_p. */
17039 return ((TREE_CODE (decl) == FUNCTION_DECL
17040 && DECL_DECLARED_INLINE_P (decl))
17041 /* And we need to instantiate static data members so that
17042 their initializers are available in integral constant
17044 || (TREE_CODE (decl) == VAR_DECL
17045 && decl_maybe_constant_var_p (decl)));
17048 /* Produce the definition of D, a _DECL generated from a template. If
17049 DEFER_OK is nonzero, then we don't have to actually do the
17050 instantiation now; we just have to do it sometime. Normally it is
17051 an error if this is an explicit instantiation but D is undefined.
17052 EXPL_INST_CLASS_MEM_P is true iff D is a member of an
17053 explicitly instantiated class template. */
17056 instantiate_decl (tree d, int defer_ok,
17057 bool expl_inst_class_mem_p)
17059 tree tmpl = DECL_TI_TEMPLATE (d);
17066 bool pattern_defined;
17068 location_t saved_loc = input_location;
17071 /* This function should only be used to instantiate templates for
17072 functions and static member variables. */
17073 gcc_assert (TREE_CODE (d) == FUNCTION_DECL
17074 || TREE_CODE (d) == VAR_DECL);
17076 /* Variables are never deferred; if instantiation is required, they
17077 are instantiated right away. That allows for better code in the
17078 case that an expression refers to the value of the variable --
17079 if the variable has a constant value the referring expression can
17080 take advantage of that fact. */
17081 if (TREE_CODE (d) == VAR_DECL
17082 || DECL_DECLARED_CONSTEXPR_P (d))
17085 /* Don't instantiate cloned functions. Instead, instantiate the
17086 functions they cloned. */
17087 if (TREE_CODE (d) == FUNCTION_DECL && DECL_CLONED_FUNCTION_P (d))
17088 d = DECL_CLONED_FUNCTION (d);
17090 if (DECL_TEMPLATE_INSTANTIATED (d)
17091 || DECL_TEMPLATE_SPECIALIZATION (d))
17092 /* D has already been instantiated or explicitly specialized, so
17093 there's nothing for us to do here.
17095 It might seem reasonable to check whether or not D is an explicit
17096 instantiation, and, if so, stop here. But when an explicit
17097 instantiation is deferred until the end of the compilation,
17098 DECL_EXPLICIT_INSTANTIATION is set, even though we still need to do
17099 the instantiation. */
17102 /* Check to see whether we know that this template will be
17103 instantiated in some other file, as with "extern template"
17105 external_p = (DECL_INTERFACE_KNOWN (d) && DECL_REALLY_EXTERN (d));
17107 /* In general, we do not instantiate such templates. */
17108 if (external_p && !always_instantiate_p (d))
17111 gen_tmpl = most_general_template (tmpl);
17112 gen_args = DECL_TI_ARGS (d);
17114 if (tmpl != gen_tmpl)
17115 /* We should already have the extra args. */
17116 gcc_assert (TMPL_PARMS_DEPTH (DECL_TEMPLATE_PARMS (gen_tmpl))
17117 == TMPL_ARGS_DEPTH (gen_args));
17118 /* And what's in the hash table should match D. */
17119 gcc_assert ((spec = retrieve_specialization (gen_tmpl, gen_args, 0)) == d
17120 || spec == NULL_TREE);
17122 /* This needs to happen before any tsubsting. */
17123 if (! push_tinst_level (d))
17126 timevar_push (TV_PARSE);
17128 /* Set TD to the template whose DECL_TEMPLATE_RESULT is the pattern
17129 for the instantiation. */
17130 td = template_for_substitution (d);
17131 code_pattern = DECL_TEMPLATE_RESULT (td);
17133 /* We should never be trying to instantiate a member of a class
17134 template or partial specialization. */
17135 gcc_assert (d != code_pattern);
17137 if ((DECL_NAMESPACE_SCOPE_P (d) && !DECL_INITIALIZED_IN_CLASS_P (d))
17138 || DECL_TEMPLATE_SPECIALIZATION (td))
17139 /* In the case of a friend template whose definition is provided
17140 outside the class, we may have too many arguments. Drop the
17141 ones we don't need. The same is true for specializations. */
17142 args = get_innermost_template_args
17143 (gen_args, TMPL_PARMS_DEPTH (DECL_TEMPLATE_PARMS (td)));
17147 if (TREE_CODE (d) == FUNCTION_DECL)
17148 pattern_defined = (DECL_SAVED_TREE (code_pattern) != NULL_TREE);
17150 pattern_defined = ! DECL_IN_AGGR_P (code_pattern);
17152 /* We may be in the middle of deferred access check. Disable it now. */
17153 push_deferring_access_checks (dk_no_deferred);
17155 /* Unless an explicit instantiation directive has already determined
17156 the linkage of D, remember that a definition is available for
17158 if (pattern_defined
17159 && !DECL_INTERFACE_KNOWN (d)
17160 && !DECL_NOT_REALLY_EXTERN (d))
17161 mark_definable (d);
17163 DECL_SOURCE_LOCATION (td) = DECL_SOURCE_LOCATION (code_pattern);
17164 DECL_SOURCE_LOCATION (d) = DECL_SOURCE_LOCATION (code_pattern);
17165 input_location = DECL_SOURCE_LOCATION (d);
17167 /* If D is a member of an explicitly instantiated class template,
17168 and no definition is available, treat it like an implicit
17170 if (!pattern_defined && expl_inst_class_mem_p
17171 && DECL_EXPLICIT_INSTANTIATION (d))
17173 DECL_NOT_REALLY_EXTERN (d) = 0;
17174 DECL_INTERFACE_KNOWN (d) = 0;
17175 SET_DECL_IMPLICIT_INSTANTIATION (d);
17178 /* Recheck the substitutions to obtain any warning messages
17179 about ignoring cv qualifiers. Don't do this for artificial decls,
17180 as it breaks the context-sensitive substitution for lambda op(). */
17181 if (!defer_ok && !DECL_ARTIFICIAL (d))
17183 tree gen = DECL_TEMPLATE_RESULT (gen_tmpl);
17184 tree type = TREE_TYPE (gen);
17186 /* Make sure that we can see identifiers, and compute access
17187 correctly. D is already the target FUNCTION_DECL with the
17189 push_access_scope (d);
17191 if (TREE_CODE (gen) == FUNCTION_DECL)
17193 tsubst (DECL_ARGUMENTS (gen), gen_args, tf_warning_or_error, d);
17194 tsubst_exception_specification (type, gen_args, tf_warning_or_error,
17196 /* Don't simply tsubst the function type, as that will give
17197 duplicate warnings about poor parameter qualifications.
17198 The function arguments are the same as the decl_arguments
17199 without the top level cv qualifiers. */
17200 type = TREE_TYPE (type);
17202 tsubst (type, gen_args, tf_warning_or_error, d);
17204 pop_access_scope (d);
17207 /* Defer all other templates, unless we have been explicitly
17208 forbidden from doing so. */
17209 if (/* If there is no definition, we cannot instantiate the
17212 /* If it's OK to postpone instantiation, do so. */
17214 /* If this is a static data member that will be defined
17215 elsewhere, we don't want to instantiate the entire data
17216 member, but we do want to instantiate the initializer so that
17217 we can substitute that elsewhere. */
17218 || (external_p && TREE_CODE (d) == VAR_DECL))
17220 /* The definition of the static data member is now required so
17221 we must substitute the initializer. */
17222 if (TREE_CODE (d) == VAR_DECL
17223 && !DECL_INITIAL (d)
17224 && DECL_INITIAL (code_pattern))
17228 bool const_init = false;
17230 ns = decl_namespace_context (d);
17231 push_nested_namespace (ns);
17232 push_nested_class (DECL_CONTEXT (d));
17233 init = tsubst_expr (DECL_INITIAL (code_pattern),
17235 tf_warning_or_error, NULL_TREE,
17236 /*integral_constant_expression_p=*/false);
17237 /* Make sure the initializer is still constant, in case of
17238 circular dependency (template/instantiate6.C). */
17240 = DECL_INITIALIZED_BY_CONSTANT_EXPRESSION_P (code_pattern);
17241 cp_finish_decl (d, init, /*init_const_expr_p=*/const_init,
17242 /*asmspec_tree=*/NULL_TREE,
17243 LOOKUP_ONLYCONVERTING);
17244 pop_nested_class ();
17245 pop_nested_namespace (ns);
17248 /* We restore the source position here because it's used by
17249 add_pending_template. */
17250 input_location = saved_loc;
17252 if (at_eof && !pattern_defined
17253 && DECL_EXPLICIT_INSTANTIATION (d)
17254 && DECL_NOT_REALLY_EXTERN (d))
17257 The definition of a non-exported function template, a
17258 non-exported member function template, or a non-exported
17259 member function or static data member of a class template
17260 shall be present in every translation unit in which it is
17261 explicitly instantiated. */
17262 permerror (input_location, "explicit instantiation of %qD "
17263 "but no definition available", d);
17265 /* If we're in unevaluated context, we just wanted to get the
17266 constant value; this isn't an odr use, so don't queue
17267 a full instantiation. */
17268 if (cp_unevaluated_operand != 0)
17270 /* ??? Historically, we have instantiated inline functions, even
17271 when marked as "extern template". */
17272 if (!(external_p && TREE_CODE (d) == VAR_DECL))
17273 add_pending_template (d);
17276 /* Tell the repository that D is available in this translation unit
17277 -- and see if it is supposed to be instantiated here. */
17278 if (TREE_PUBLIC (d) && !DECL_REALLY_EXTERN (d) && !repo_emit_p (d))
17280 /* In a PCH file, despite the fact that the repository hasn't
17281 requested instantiation in the PCH it is still possible that
17282 an instantiation will be required in a file that includes the
17285 add_pending_template (d);
17286 /* Instantiate inline functions so that the inliner can do its
17287 job, even though we'll not be emitting a copy of this
17289 if (!(TREE_CODE (d) == FUNCTION_DECL && possibly_inlined_p (d)))
17293 need_push = !cfun || !global_bindings_p ();
17295 push_to_top_level ();
17297 /* Mark D as instantiated so that recursive calls to
17298 instantiate_decl do not try to instantiate it again. */
17299 DECL_TEMPLATE_INSTANTIATED (d) = 1;
17301 /* Regenerate the declaration in case the template has been modified
17302 by a subsequent redeclaration. */
17303 regenerate_decl_from_template (d, td);
17305 /* We already set the file and line above. Reset them now in case
17306 they changed as a result of calling regenerate_decl_from_template. */
17307 input_location = DECL_SOURCE_LOCATION (d);
17309 if (TREE_CODE (d) == VAR_DECL)
17312 bool const_init = false;
17314 /* Clear out DECL_RTL; whatever was there before may not be right
17315 since we've reset the type of the declaration. */
17316 SET_DECL_RTL (d, NULL);
17317 DECL_IN_AGGR_P (d) = 0;
17319 /* The initializer is placed in DECL_INITIAL by
17320 regenerate_decl_from_template so we don't need to
17321 push/pop_access_scope again here. Pull it out so that
17322 cp_finish_decl can process it. */
17323 init = DECL_INITIAL (d);
17324 DECL_INITIAL (d) = NULL_TREE;
17325 DECL_INITIALIZED_P (d) = 0;
17327 /* Clear DECL_EXTERNAL so that cp_finish_decl will process the
17328 initializer. That function will defer actual emission until
17329 we have a chance to determine linkage. */
17330 DECL_EXTERNAL (d) = 0;
17332 /* Enter the scope of D so that access-checking works correctly. */
17333 push_nested_class (DECL_CONTEXT (d));
17334 const_init = DECL_INITIALIZED_BY_CONSTANT_EXPRESSION_P (code_pattern);
17335 cp_finish_decl (d, init, const_init, NULL_TREE, 0);
17336 pop_nested_class ();
17338 else if (TREE_CODE (d) == FUNCTION_DECL)
17340 htab_t saved_local_specializations;
17345 /* Save away the current list, in case we are instantiating one
17346 template from within the body of another. */
17347 saved_local_specializations = local_specializations;
17349 /* Set up the list of local specializations. */
17350 local_specializations = htab_create (37,
17351 hash_local_specialization,
17352 eq_local_specializations,
17355 /* Set up context. */
17356 start_preparsed_function (d, NULL_TREE, SF_PRE_PARSED);
17358 /* Create substitution entries for the parameters. */
17359 subst_decl = DECL_TEMPLATE_RESULT (template_for_substitution (d));
17360 tmpl_parm = DECL_ARGUMENTS (subst_decl);
17361 spec_parm = DECL_ARGUMENTS (d);
17362 if (DECL_NONSTATIC_MEMBER_FUNCTION_P (d))
17364 register_local_specialization (spec_parm, tmpl_parm);
17365 spec_parm = skip_artificial_parms_for (d, spec_parm);
17366 tmpl_parm = skip_artificial_parms_for (subst_decl, tmpl_parm);
17368 while (tmpl_parm && !FUNCTION_PARAMETER_PACK_P (tmpl_parm))
17370 register_local_specialization (spec_parm, tmpl_parm);
17371 tmpl_parm = DECL_CHAIN (tmpl_parm);
17372 spec_parm = DECL_CHAIN (spec_parm);
17374 if (tmpl_parm && FUNCTION_PARAMETER_PACK_P (tmpl_parm))
17376 /* Register the (value) argument pack as a specialization of
17377 TMPL_PARM, then move on. */
17378 tree argpack = make_fnparm_pack (spec_parm);
17379 register_local_specialization (argpack, tmpl_parm);
17380 tmpl_parm = DECL_CHAIN (tmpl_parm);
17381 spec_parm = NULL_TREE;
17383 gcc_assert (!spec_parm);
17385 /* Substitute into the body of the function. */
17386 tsubst_expr (DECL_SAVED_TREE (code_pattern), args,
17387 tf_warning_or_error, tmpl,
17388 /*integral_constant_expression_p=*/false);
17390 /* Set the current input_location to the end of the function
17391 so that finish_function knows where we are. */
17392 input_location = DECL_STRUCT_FUNCTION (code_pattern)->function_end_locus;
17394 /* We don't need the local specializations any more. */
17395 htab_delete (local_specializations);
17396 local_specializations = saved_local_specializations;
17398 /* Finish the function. */
17399 d = finish_function (0);
17400 expand_or_defer_fn (d);
17403 /* We're not deferring instantiation any more. */
17404 TI_PENDING_TEMPLATE_FLAG (DECL_TEMPLATE_INFO (d)) = 0;
17407 pop_from_top_level ();
17410 input_location = saved_loc;
17411 pop_deferring_access_checks ();
17412 pop_tinst_level ();
17414 timevar_pop (TV_PARSE);
17419 /* Run through the list of templates that we wish we could
17420 instantiate, and instantiate any we can. RETRIES is the
17421 number of times we retry pending template instantiation. */
17424 instantiate_pending_templates (int retries)
17427 location_t saved_loc = input_location;
17429 /* Instantiating templates may trigger vtable generation. This in turn
17430 may require further template instantiations. We place a limit here
17431 to avoid infinite loop. */
17432 if (pending_templates && retries >= max_tinst_depth)
17434 tree decl = pending_templates->tinst->decl;
17436 error ("template instantiation depth exceeds maximum of %d"
17437 " instantiating %q+D, possibly from virtual table generation"
17438 " (use -ftemplate-depth= to increase the maximum)",
17439 max_tinst_depth, decl);
17440 if (TREE_CODE (decl) == FUNCTION_DECL)
17441 /* Pretend that we defined it. */
17442 DECL_INITIAL (decl) = error_mark_node;
17448 struct pending_template **t = &pending_templates;
17449 struct pending_template *last = NULL;
17453 tree instantiation = reopen_tinst_level ((*t)->tinst);
17454 bool complete = false;
17456 if (TYPE_P (instantiation))
17460 if (!COMPLETE_TYPE_P (instantiation))
17462 instantiate_class_template (instantiation);
17463 if (CLASSTYPE_TEMPLATE_INSTANTIATION (instantiation))
17464 for (fn = TYPE_METHODS (instantiation);
17466 fn = TREE_CHAIN (fn))
17467 if (! DECL_ARTIFICIAL (fn))
17468 instantiate_decl (fn,
17470 /*expl_inst_class_mem_p=*/false);
17471 if (COMPLETE_TYPE_P (instantiation))
17475 complete = COMPLETE_TYPE_P (instantiation);
17479 if (!DECL_TEMPLATE_SPECIALIZATION (instantiation)
17480 && !DECL_TEMPLATE_INSTANTIATED (instantiation))
17483 = instantiate_decl (instantiation,
17485 /*expl_inst_class_mem_p=*/false);
17486 if (DECL_TEMPLATE_INSTANTIATED (instantiation))
17490 complete = (DECL_TEMPLATE_SPECIALIZATION (instantiation)
17491 || DECL_TEMPLATE_INSTANTIATED (instantiation));
17495 /* If INSTANTIATION has been instantiated, then we don't
17496 need to consider it again in the future. */
17504 current_tinst_level = NULL;
17506 last_pending_template = last;
17508 while (reconsider);
17510 input_location = saved_loc;
17513 /* Substitute ARGVEC into T, which is a list of initializers for
17514 either base class or a non-static data member. The TREE_PURPOSEs
17515 are DECLs, and the TREE_VALUEs are the initializer values. Used by
17516 instantiate_decl. */
17519 tsubst_initializer_list (tree t, tree argvec)
17521 tree inits = NULL_TREE;
17523 for (; t; t = TREE_CHAIN (t))
17527 tree expanded_bases = NULL_TREE;
17528 tree expanded_arguments = NULL_TREE;
17531 if (TREE_CODE (TREE_PURPOSE (t)) == TYPE_PACK_EXPANSION)
17536 /* Expand the base class expansion type into separate base
17538 expanded_bases = tsubst_pack_expansion (TREE_PURPOSE (t), argvec,
17539 tf_warning_or_error,
17541 if (expanded_bases == error_mark_node)
17544 /* We'll be building separate TREE_LISTs of arguments for
17546 len = TREE_VEC_LENGTH (expanded_bases);
17547 expanded_arguments = make_tree_vec (len);
17548 for (i = 0; i < len; i++)
17549 TREE_VEC_ELT (expanded_arguments, i) = NULL_TREE;
17551 /* Build a dummy EXPR_PACK_EXPANSION that will be used to
17552 expand each argument in the TREE_VALUE of t. */
17553 expr = make_node (EXPR_PACK_EXPANSION);
17554 PACK_EXPANSION_PARAMETER_PACKS (expr) =
17555 PACK_EXPANSION_PARAMETER_PACKS (TREE_PURPOSE (t));
17557 if (TREE_VALUE (t) == void_type_node)
17558 /* VOID_TYPE_NODE is used to indicate
17559 value-initialization. */
17561 for (i = 0; i < len; i++)
17562 TREE_VEC_ELT (expanded_arguments, i) = void_type_node;
17566 /* Substitute parameter packs into each argument in the
17568 in_base_initializer = 1;
17569 for (arg = TREE_VALUE (t); arg; arg = TREE_CHAIN (arg))
17571 tree expanded_exprs;
17573 /* Expand the argument. */
17574 SET_PACK_EXPANSION_PATTERN (expr, TREE_VALUE (arg));
17576 = tsubst_pack_expansion (expr, argvec,
17577 tf_warning_or_error,
17579 if (expanded_exprs == error_mark_node)
17582 /* Prepend each of the expanded expressions to the
17583 corresponding TREE_LIST in EXPANDED_ARGUMENTS. */
17584 for (i = 0; i < len; i++)
17586 TREE_VEC_ELT (expanded_arguments, i) =
17587 tree_cons (NULL_TREE,
17588 TREE_VEC_ELT (expanded_exprs, i),
17589 TREE_VEC_ELT (expanded_arguments, i));
17592 in_base_initializer = 0;
17594 /* Reverse all of the TREE_LISTs in EXPANDED_ARGUMENTS,
17595 since we built them backwards. */
17596 for (i = 0; i < len; i++)
17598 TREE_VEC_ELT (expanded_arguments, i) =
17599 nreverse (TREE_VEC_ELT (expanded_arguments, i));
17604 for (i = 0; i < len; ++i)
17606 if (expanded_bases)
17608 decl = TREE_VEC_ELT (expanded_bases, i);
17609 decl = expand_member_init (decl);
17610 init = TREE_VEC_ELT (expanded_arguments, i);
17614 decl = tsubst_copy (TREE_PURPOSE (t), argvec,
17615 tf_warning_or_error, NULL_TREE);
17617 decl = expand_member_init (decl);
17618 if (decl && !DECL_P (decl))
17619 in_base_initializer = 1;
17621 init = TREE_VALUE (t);
17622 if (init != void_type_node)
17623 init = tsubst_expr (init, argvec,
17624 tf_warning_or_error, NULL_TREE,
17625 /*integral_constant_expression_p=*/false);
17626 in_base_initializer = 0;
17631 init = build_tree_list (decl, init);
17632 TREE_CHAIN (init) = inits;
17640 /* Set CURRENT_ACCESS_SPECIFIER based on the protection of DECL. */
17643 set_current_access_from_decl (tree decl)
17645 if (TREE_PRIVATE (decl))
17646 current_access_specifier = access_private_node;
17647 else if (TREE_PROTECTED (decl))
17648 current_access_specifier = access_protected_node;
17650 current_access_specifier = access_public_node;
17653 /* Instantiate an enumerated type. TAG is the template type, NEWTAG
17654 is the instantiation (which should have been created with
17655 start_enum) and ARGS are the template arguments to use. */
17658 tsubst_enum (tree tag, tree newtag, tree args)
17662 if (SCOPED_ENUM_P (newtag))
17663 begin_scope (sk_scoped_enum, newtag);
17665 for (e = TYPE_VALUES (tag); e; e = TREE_CHAIN (e))
17670 decl = TREE_VALUE (e);
17671 /* Note that in a template enum, the TREE_VALUE is the
17672 CONST_DECL, not the corresponding INTEGER_CST. */
17673 value = tsubst_expr (DECL_INITIAL (decl),
17674 args, tf_warning_or_error, NULL_TREE,
17675 /*integral_constant_expression_p=*/true);
17677 /* Give this enumeration constant the correct access. */
17678 set_current_access_from_decl (decl);
17680 /* Actually build the enumerator itself. */
17682 (DECL_NAME (decl), value, newtag, DECL_SOURCE_LOCATION (decl));
17685 if (SCOPED_ENUM_P (newtag))
17688 finish_enum_value_list (newtag);
17689 finish_enum (newtag);
17691 DECL_SOURCE_LOCATION (TYPE_NAME (newtag))
17692 = DECL_SOURCE_LOCATION (TYPE_NAME (tag));
17695 /* DECL is a FUNCTION_DECL that is a template specialization. Return
17696 its type -- but without substituting the innermost set of template
17697 arguments. So, innermost set of template parameters will appear in
17701 get_mostly_instantiated_function_type (tree decl)
17709 tmpl = most_general_template (DECL_TI_TEMPLATE (decl));
17710 targs = DECL_TI_ARGS (decl);
17711 tparms = DECL_TEMPLATE_PARMS (tmpl);
17712 parm_depth = TMPL_PARMS_DEPTH (tparms);
17714 /* There should be as many levels of arguments as there are levels
17716 gcc_assert (parm_depth == TMPL_ARGS_DEPTH (targs));
17718 fn_type = TREE_TYPE (tmpl);
17720 if (parm_depth == 1)
17721 /* No substitution is necessary. */
17725 int i, save_access_control;
17728 /* Replace the innermost level of the TARGS with NULL_TREEs to
17729 let tsubst know not to substitute for those parameters. */
17730 partial_args = make_tree_vec (TREE_VEC_LENGTH (targs));
17731 for (i = 1; i < TMPL_ARGS_DEPTH (targs); ++i)
17732 SET_TMPL_ARGS_LEVEL (partial_args, i,
17733 TMPL_ARGS_LEVEL (targs, i));
17734 SET_TMPL_ARGS_LEVEL (partial_args,
17735 TMPL_ARGS_DEPTH (targs),
17736 make_tree_vec (DECL_NTPARMS (tmpl)));
17738 /* Disable access control as this function is used only during
17740 save_access_control = flag_access_control;
17741 flag_access_control = 0;
17743 ++processing_template_decl;
17744 /* Now, do the (partial) substitution to figure out the
17745 appropriate function type. */
17746 fn_type = tsubst (fn_type, partial_args, tf_error, NULL_TREE);
17747 --processing_template_decl;
17749 /* Substitute into the template parameters to obtain the real
17750 innermost set of parameters. This step is important if the
17751 innermost set of template parameters contains value
17752 parameters whose types depend on outer template parameters. */
17753 TREE_VEC_LENGTH (partial_args)--;
17754 tparms = tsubst_template_parms (tparms, partial_args, tf_error);
17756 flag_access_control = save_access_control;
17762 /* Return truthvalue if we're processing a template different from
17763 the last one involved in diagnostics. */
17765 problematic_instantiation_changed (void)
17767 return last_template_error_tick != tinst_level_tick;
17770 /* Remember current template involved in diagnostics. */
17772 record_last_problematic_instantiation (void)
17774 last_template_error_tick = tinst_level_tick;
17777 struct tinst_level *
17778 current_instantiation (void)
17780 return current_tinst_level;
17783 /* [temp.param] Check that template non-type parm TYPE is of an allowable
17784 type. Return zero for ok, nonzero for disallowed. Issue error and
17785 warning messages under control of COMPLAIN. */
17788 invalid_nontype_parm_type_p (tree type, tsubst_flags_t complain)
17790 if (INTEGRAL_OR_ENUMERATION_TYPE_P (type))
17792 else if (POINTER_TYPE_P (type))
17794 else if (TYPE_PTR_TO_MEMBER_P (type))
17796 else if (TREE_CODE (type) == TEMPLATE_TYPE_PARM)
17798 else if (TREE_CODE (type) == TYPENAME_TYPE)
17801 if (complain & tf_error)
17802 error ("%q#T is not a valid type for a template constant parameter", type);
17806 /* Returns TRUE if TYPE is dependent, in the sense of [temp.dep.type].
17807 Assumes that TYPE really is a type, and not the ERROR_MARK_NODE.*/
17810 dependent_type_p_r (tree type)
17816 A type is dependent if it is:
17818 -- a template parameter. Template template parameters are types
17819 for us (since TYPE_P holds true for them) so we handle
17821 if (TREE_CODE (type) == TEMPLATE_TYPE_PARM
17822 || TREE_CODE (type) == TEMPLATE_TEMPLATE_PARM)
17824 /* -- a qualified-id with a nested-name-specifier which contains a
17825 class-name that names a dependent type or whose unqualified-id
17826 names a dependent type. */
17827 if (TREE_CODE (type) == TYPENAME_TYPE)
17829 /* -- a cv-qualified type where the cv-unqualified type is
17831 type = TYPE_MAIN_VARIANT (type);
17832 /* -- a compound type constructed from any dependent type. */
17833 if (TYPE_PTR_TO_MEMBER_P (type))
17834 return (dependent_type_p (TYPE_PTRMEM_CLASS_TYPE (type))
17835 || dependent_type_p (TYPE_PTRMEM_POINTED_TO_TYPE
17837 else if (TREE_CODE (type) == POINTER_TYPE
17838 || TREE_CODE (type) == REFERENCE_TYPE)
17839 return dependent_type_p (TREE_TYPE (type));
17840 else if (TREE_CODE (type) == FUNCTION_TYPE
17841 || TREE_CODE (type) == METHOD_TYPE)
17845 if (dependent_type_p (TREE_TYPE (type)))
17847 for (arg_type = TYPE_ARG_TYPES (type);
17849 arg_type = TREE_CHAIN (arg_type))
17850 if (dependent_type_p (TREE_VALUE (arg_type)))
17854 /* -- an array type constructed from any dependent type or whose
17855 size is specified by a constant expression that is
17858 We checked for type- and value-dependence of the bounds in
17859 compute_array_index_type, so TYPE_DEPENDENT_P is already set. */
17860 if (TREE_CODE (type) == ARRAY_TYPE)
17862 if (TYPE_DOMAIN (type)
17863 && dependent_type_p (TYPE_DOMAIN (type)))
17865 return dependent_type_p (TREE_TYPE (type));
17868 /* -- a template-id in which either the template name is a template
17870 if (TREE_CODE (type) == BOUND_TEMPLATE_TEMPLATE_PARM)
17872 /* ... or any of the template arguments is a dependent type or
17873 an expression that is type-dependent or value-dependent. */
17874 else if (CLASS_TYPE_P (type) && CLASSTYPE_TEMPLATE_INFO (type)
17875 && (any_dependent_template_arguments_p
17876 (INNERMOST_TEMPLATE_ARGS (CLASSTYPE_TI_ARGS (type)))))
17879 /* All TYPEOF_TYPEs and DECLTYPE_TYPEs are dependent; if the
17880 argument of the `typeof' expression is not type-dependent, then
17881 it should already been have resolved. */
17882 if (TREE_CODE (type) == TYPEOF_TYPE
17883 || TREE_CODE (type) == DECLTYPE_TYPE)
17886 /* A template argument pack is dependent if any of its packed
17888 if (TREE_CODE (type) == TYPE_ARGUMENT_PACK)
17890 tree args = ARGUMENT_PACK_ARGS (type);
17891 int i, len = TREE_VEC_LENGTH (args);
17892 for (i = 0; i < len; ++i)
17893 if (dependent_template_arg_p (TREE_VEC_ELT (args, i)))
17897 /* All TYPE_PACK_EXPANSIONs are dependent, because parameter packs must
17898 be template parameters. */
17899 if (TREE_CODE (type) == TYPE_PACK_EXPANSION)
17902 /* The standard does not specifically mention types that are local
17903 to template functions or local classes, but they should be
17904 considered dependent too. For example:
17906 template <int I> void f() {
17911 The size of `E' cannot be known until the value of `I' has been
17912 determined. Therefore, `E' must be considered dependent. */
17913 scope = TYPE_CONTEXT (type);
17914 if (scope && TYPE_P (scope))
17915 return dependent_type_p (scope);
17916 else if (scope && TREE_CODE (scope) == FUNCTION_DECL)
17917 return type_dependent_expression_p (scope);
17919 /* Other types are non-dependent. */
17923 /* Returns TRUE if TYPE is dependent, in the sense of
17924 [temp.dep.type]. Note that a NULL type is considered dependent. */
17927 dependent_type_p (tree type)
17929 /* If there are no template parameters in scope, then there can't be
17930 any dependent types. */
17931 if (!processing_template_decl)
17933 /* If we are not processing a template, then nobody should be
17934 providing us with a dependent type. */
17936 gcc_assert (TREE_CODE (type) != TEMPLATE_TYPE_PARM || is_auto (type));
17940 /* If the type is NULL, we have not computed a type for the entity
17941 in question; in that case, the type is dependent. */
17945 /* Erroneous types can be considered non-dependent. */
17946 if (type == error_mark_node)
17949 /* If we have not already computed the appropriate value for TYPE,
17951 if (!TYPE_DEPENDENT_P_VALID (type))
17953 TYPE_DEPENDENT_P (type) = dependent_type_p_r (type);
17954 TYPE_DEPENDENT_P_VALID (type) = 1;
17957 return TYPE_DEPENDENT_P (type);
17960 /* Returns TRUE if SCOPE is a dependent scope, in which we can't do any
17961 lookup. In other words, a dependent type that is not the current
17965 dependent_scope_p (tree scope)
17967 return (scope && TYPE_P (scope) && dependent_type_p (scope)
17968 && !currently_open_class (scope));
17971 /* Returns TRUE if the EXPRESSION is value-dependent, in the sense of
17972 [temp.dep.constexpr]. EXPRESSION is already known to be a constant
17975 /* Note that this predicate is not appropriate for general expressions;
17976 only constant expressions (that satisfy potential_constant_expression)
17977 can be tested for value dependence.
17979 We should really also have a predicate for "instantiation-dependent".
17981 fold_non_dependent_expr: fold if constant and not type-dependent and not value-dependent.
17982 (what about instantiation-dependent constant-expressions?)
17983 is_late_template_attribute: defer if instantiation-dependent.
17984 compute_array_index_type: proceed if constant and not t- or v-dependent
17985 if instantiation-dependent, need to remember full expression
17986 uses_template_parms: FIXME - need to audit callers
17987 tsubst_decl [function_decl]: Why is this using value_dependent_expression_p?
17988 dependent_type_p [array_type]: dependent if index type is dependent
17990 static_assert - instantiation-dependent */
17993 value_dependent_expression_p (tree expression)
17995 if (!processing_template_decl)
17998 /* A name declared with a dependent type. */
17999 if (DECL_P (expression) && type_dependent_expression_p (expression))
18002 switch (TREE_CODE (expression))
18004 case IDENTIFIER_NODE:
18005 /* A name that has not been looked up -- must be dependent. */
18008 case TEMPLATE_PARM_INDEX:
18009 /* A non-type template parm. */
18013 /* A non-type template parm. */
18014 if (DECL_TEMPLATE_PARM_P (expression))
18016 return value_dependent_expression_p (DECL_INITIAL (expression));
18019 /* A constant with integral or enumeration type and is initialized
18020 with an expression that is value-dependent. */
18021 if (DECL_INITIAL (expression)
18022 && INTEGRAL_OR_ENUMERATION_TYPE_P (TREE_TYPE (expression))
18023 && value_dependent_expression_p (DECL_INITIAL (expression)))
18027 case DYNAMIC_CAST_EXPR:
18028 case STATIC_CAST_EXPR:
18029 case CONST_CAST_EXPR:
18030 case REINTERPRET_CAST_EXPR:
18032 /* These expressions are value-dependent if the type to which
18033 the cast occurs is dependent or the expression being casted
18034 is value-dependent. */
18036 tree type = TREE_TYPE (expression);
18038 if (dependent_type_p (type))
18041 /* A functional cast has a list of operands. */
18042 expression = TREE_OPERAND (expression, 0);
18045 /* If there are no operands, it must be an expression such
18046 as "int()". This should not happen for aggregate types
18047 because it would form non-constant expressions. */
18048 gcc_assert (cxx_dialect >= cxx0x
18049 || INTEGRAL_OR_ENUMERATION_TYPE_P (type));
18054 if (TREE_CODE (expression) == TREE_LIST)
18055 return any_value_dependent_elements_p (expression);
18057 return value_dependent_expression_p (expression);
18062 /* A `sizeof' expression is value-dependent if the operand is
18063 type-dependent or is a pack expansion. */
18064 expression = TREE_OPERAND (expression, 0);
18065 if (PACK_EXPANSION_P (expression))
18067 else if (TYPE_P (expression))
18068 return dependent_type_p (expression);
18069 return type_dependent_expression_p (expression);
18071 case AT_ENCODE_EXPR:
18072 /* An 'encode' expression is value-dependent if the operand is
18074 expression = TREE_OPERAND (expression, 0);
18075 return dependent_type_p (expression);
18077 case NOEXCEPT_EXPR:
18078 expression = TREE_OPERAND (expression, 0);
18079 /* FIXME why check value-dependency? */
18080 return (type_dependent_expression_p (expression)
18081 || value_dependent_expression_p (expression));
18085 tree name = TREE_OPERAND (expression, 1);
18086 return value_dependent_expression_p (name);
18089 case COMPONENT_REF:
18090 return (value_dependent_expression_p (TREE_OPERAND (expression, 0))
18091 || value_dependent_expression_p (TREE_OPERAND (expression, 1)));
18093 case NONTYPE_ARGUMENT_PACK:
18094 /* A NONTYPE_ARGUMENT_PACK is value-dependent if any packed argument
18095 is value-dependent. */
18097 tree values = ARGUMENT_PACK_ARGS (expression);
18098 int i, len = TREE_VEC_LENGTH (values);
18100 for (i = 0; i < len; ++i)
18101 if (value_dependent_expression_p (TREE_VEC_ELT (values, i)))
18109 tree type2 = TRAIT_EXPR_TYPE2 (expression);
18110 return (dependent_type_p (TRAIT_EXPR_TYPE1 (expression))
18111 || (type2 ? dependent_type_p (type2) : false));
18115 return ((value_dependent_expression_p (TREE_OPERAND (expression, 0)))
18116 || (value_dependent_expression_p (TREE_OPERAND (expression, 2))));
18119 return ((value_dependent_expression_p (TREE_OPERAND (expression, 0)))
18120 || (value_dependent_expression_p (TREE_OPERAND (expression, 1))));
18124 tree op = TREE_OPERAND (expression, 0);
18125 return (value_dependent_expression_p (op)
18126 || has_value_dependent_address (op));
18131 tree fn = get_callee_fndecl (expression);
18133 if (!fn && value_dependent_expression_p (CALL_EXPR_FN (expression)))
18135 nargs = call_expr_nargs (expression);
18136 for (i = 0; i < nargs; ++i)
18138 tree op = CALL_EXPR_ARG (expression, i);
18139 /* In a call to a constexpr member function, look through the
18140 implicit ADDR_EXPR on the object argument so that it doesn't
18141 cause the call to be considered value-dependent. We also
18142 look through it in potential_constant_expression. */
18143 if (i == 0 && fn && DECL_DECLARED_CONSTEXPR_P (fn)
18144 && DECL_NONSTATIC_MEMBER_FUNCTION_P (fn)
18145 && TREE_CODE (op) == ADDR_EXPR)
18146 op = TREE_OPERAND (op, 0);
18147 if (value_dependent_expression_p (op))
18154 /* A constant expression is value-dependent if any subexpression is
18155 value-dependent. */
18156 switch (TREE_CODE_CLASS (TREE_CODE (expression)))
18158 case tcc_reference:
18160 return (value_dependent_expression_p
18161 (TREE_OPERAND (expression, 0)));
18163 case tcc_comparison:
18165 return ((value_dependent_expression_p
18166 (TREE_OPERAND (expression, 0)))
18167 || (value_dependent_expression_p
18168 (TREE_OPERAND (expression, 1))));
18170 case tcc_expression:
18174 for (i = 0; i < TREE_OPERAND_LENGTH (expression); ++i)
18175 /* In some cases, some of the operands may be missing.
18176 (For example, in the case of PREDECREMENT_EXPR, the
18177 amount to increment by may be missing.) That doesn't
18178 make the expression dependent. */
18179 if (TREE_OPERAND (expression, i)
18180 && (value_dependent_expression_p
18181 (TREE_OPERAND (expression, i))))
18191 /* The expression is not value-dependent. */
18195 /* Returns TRUE if the EXPRESSION is type-dependent, in the sense of
18196 [temp.dep.expr]. Note that an expression with no type is
18197 considered dependent. Other parts of the compiler arrange for an
18198 expression with type-dependent subexpressions to have no type, so
18199 this function doesn't have to be fully recursive. */
18202 type_dependent_expression_p (tree expression)
18204 if (!processing_template_decl)
18207 if (expression == error_mark_node)
18210 /* An unresolved name is always dependent. */
18211 if (TREE_CODE (expression) == IDENTIFIER_NODE
18212 || TREE_CODE (expression) == USING_DECL)
18215 /* Some expression forms are never type-dependent. */
18216 if (TREE_CODE (expression) == PSEUDO_DTOR_EXPR
18217 || TREE_CODE (expression) == SIZEOF_EXPR
18218 || TREE_CODE (expression) == ALIGNOF_EXPR
18219 || TREE_CODE (expression) == AT_ENCODE_EXPR
18220 || TREE_CODE (expression) == NOEXCEPT_EXPR
18221 || TREE_CODE (expression) == TRAIT_EXPR
18222 || TREE_CODE (expression) == TYPEID_EXPR
18223 || TREE_CODE (expression) == DELETE_EXPR
18224 || TREE_CODE (expression) == VEC_DELETE_EXPR
18225 || TREE_CODE (expression) == THROW_EXPR)
18228 /* The types of these expressions depends only on the type to which
18229 the cast occurs. */
18230 if (TREE_CODE (expression) == DYNAMIC_CAST_EXPR
18231 || TREE_CODE (expression) == STATIC_CAST_EXPR
18232 || TREE_CODE (expression) == CONST_CAST_EXPR
18233 || TREE_CODE (expression) == REINTERPRET_CAST_EXPR
18234 || TREE_CODE (expression) == CAST_EXPR)
18235 return dependent_type_p (TREE_TYPE (expression));
18237 /* The types of these expressions depends only on the type created
18238 by the expression. */
18239 if (TREE_CODE (expression) == NEW_EXPR
18240 || TREE_CODE (expression) == VEC_NEW_EXPR)
18242 /* For NEW_EXPR tree nodes created inside a template, either
18243 the object type itself or a TREE_LIST may appear as the
18245 tree type = TREE_OPERAND (expression, 1);
18246 if (TREE_CODE (type) == TREE_LIST)
18247 /* This is an array type. We need to check array dimensions
18249 return dependent_type_p (TREE_VALUE (TREE_PURPOSE (type)))
18250 || value_dependent_expression_p
18251 (TREE_OPERAND (TREE_VALUE (type), 1));
18253 return dependent_type_p (type);
18256 if (TREE_CODE (expression) == SCOPE_REF)
18258 tree scope = TREE_OPERAND (expression, 0);
18259 tree name = TREE_OPERAND (expression, 1);
18261 /* 14.6.2.2 [temp.dep.expr]: An id-expression is type-dependent if it
18262 contains an identifier associated by name lookup with one or more
18263 declarations declared with a dependent type, or...a
18264 nested-name-specifier or qualified-id that names a member of an
18265 unknown specialization. */
18266 return (type_dependent_expression_p (name)
18267 || dependent_scope_p (scope));
18270 if (TREE_CODE (expression) == FUNCTION_DECL
18271 && DECL_LANG_SPECIFIC (expression)
18272 && DECL_TEMPLATE_INFO (expression)
18273 && (any_dependent_template_arguments_p
18274 (INNERMOST_TEMPLATE_ARGS (DECL_TI_ARGS (expression)))))
18277 if (TREE_CODE (expression) == TEMPLATE_DECL
18278 && !DECL_TEMPLATE_TEMPLATE_PARM_P (expression))
18281 if (TREE_CODE (expression) == STMT_EXPR)
18282 expression = stmt_expr_value_expr (expression);
18284 if (BRACE_ENCLOSED_INITIALIZER_P (expression))
18289 FOR_EACH_CONSTRUCTOR_VALUE (CONSTRUCTOR_ELTS (expression), i, elt)
18291 if (type_dependent_expression_p (elt))
18297 /* A static data member of the current instantiation with incomplete
18298 array type is type-dependent, as the definition and specializations
18299 can have different bounds. */
18300 if (TREE_CODE (expression) == VAR_DECL
18301 && DECL_CLASS_SCOPE_P (expression)
18302 && dependent_type_p (DECL_CONTEXT (expression))
18303 && VAR_HAD_UNKNOWN_BOUND (expression))
18306 if (TREE_TYPE (expression) == unknown_type_node)
18308 if (TREE_CODE (expression) == ADDR_EXPR)
18309 return type_dependent_expression_p (TREE_OPERAND (expression, 0));
18310 if (TREE_CODE (expression) == COMPONENT_REF
18311 || TREE_CODE (expression) == OFFSET_REF)
18313 if (type_dependent_expression_p (TREE_OPERAND (expression, 0)))
18315 expression = TREE_OPERAND (expression, 1);
18316 if (TREE_CODE (expression) == IDENTIFIER_NODE)
18319 /* SCOPE_REF with non-null TREE_TYPE is always non-dependent. */
18320 if (TREE_CODE (expression) == SCOPE_REF)
18323 if (TREE_CODE (expression) == BASELINK)
18324 expression = BASELINK_FUNCTIONS (expression);
18326 if (TREE_CODE (expression) == TEMPLATE_ID_EXPR)
18328 if (any_dependent_template_arguments_p
18329 (TREE_OPERAND (expression, 1)))
18331 expression = TREE_OPERAND (expression, 0);
18333 gcc_assert (TREE_CODE (expression) == OVERLOAD
18334 || TREE_CODE (expression) == FUNCTION_DECL);
18338 if (type_dependent_expression_p (OVL_CURRENT (expression)))
18340 expression = OVL_NEXT (expression);
18345 gcc_assert (TREE_CODE (expression) != TYPE_DECL);
18347 return (dependent_type_p (TREE_TYPE (expression)));
18350 /* Like type_dependent_expression_p, but it also works while not processing
18351 a template definition, i.e. during substitution or mangling. */
18354 type_dependent_expression_p_push (tree expr)
18357 ++processing_template_decl;
18358 b = type_dependent_expression_p (expr);
18359 --processing_template_decl;
18363 /* Returns TRUE if ARGS contains a type-dependent expression. */
18366 any_type_dependent_arguments_p (const VEC(tree,gc) *args)
18371 FOR_EACH_VEC_ELT (tree, args, i, arg)
18373 if (type_dependent_expression_p (arg))
18379 /* Returns TRUE if LIST (a TREE_LIST whose TREE_VALUEs are
18380 expressions) contains any value-dependent expressions. */
18383 any_value_dependent_elements_p (const_tree list)
18385 for (; list; list = TREE_CHAIN (list))
18386 if (value_dependent_expression_p (TREE_VALUE (list)))
18392 /* Returns TRUE if the ARG (a template argument) is dependent. */
18395 dependent_template_arg_p (tree arg)
18397 if (!processing_template_decl)
18400 /* Assume a template argument that was wrongly written by the user
18401 is dependent. This is consistent with what
18402 any_dependent_template_arguments_p [that calls this function]
18404 if (arg == error_mark_node)
18407 if (TREE_CODE (arg) == TEMPLATE_DECL
18408 || TREE_CODE (arg) == TEMPLATE_TEMPLATE_PARM)
18409 return dependent_template_p (arg);
18410 else if (ARGUMENT_PACK_P (arg))
18412 tree args = ARGUMENT_PACK_ARGS (arg);
18413 int i, len = TREE_VEC_LENGTH (args);
18414 for (i = 0; i < len; ++i)
18416 if (dependent_template_arg_p (TREE_VEC_ELT (args, i)))
18422 else if (TYPE_P (arg))
18423 return dependent_type_p (arg);
18425 return (type_dependent_expression_p (arg)
18426 || value_dependent_expression_p (arg));
18429 /* Returns true if ARGS (a collection of template arguments) contains
18430 any types that require structural equality testing. */
18433 any_template_arguments_need_structural_equality_p (tree args)
18440 if (args == error_mark_node)
18443 for (i = 0; i < TMPL_ARGS_DEPTH (args); ++i)
18445 tree level = TMPL_ARGS_LEVEL (args, i + 1);
18446 for (j = 0; j < TREE_VEC_LENGTH (level); ++j)
18448 tree arg = TREE_VEC_ELT (level, j);
18449 tree packed_args = NULL_TREE;
18452 if (ARGUMENT_PACK_P (arg))
18454 /* Look inside the argument pack. */
18455 packed_args = ARGUMENT_PACK_ARGS (arg);
18456 len = TREE_VEC_LENGTH (packed_args);
18459 for (k = 0; k < len; ++k)
18462 arg = TREE_VEC_ELT (packed_args, k);
18464 if (error_operand_p (arg))
18466 else if (TREE_CODE (arg) == TEMPLATE_DECL
18467 || TREE_CODE (arg) == TEMPLATE_TEMPLATE_PARM)
18469 else if (TYPE_P (arg) && TYPE_STRUCTURAL_EQUALITY_P (arg))
18471 else if (!TYPE_P (arg) && TREE_TYPE (arg)
18472 && TYPE_STRUCTURAL_EQUALITY_P (TREE_TYPE (arg)))
18481 /* Returns true if ARGS (a collection of template arguments) contains
18482 any dependent arguments. */
18485 any_dependent_template_arguments_p (const_tree args)
18492 if (args == error_mark_node)
18495 for (i = 0; i < TMPL_ARGS_DEPTH (args); ++i)
18497 const_tree level = TMPL_ARGS_LEVEL (args, i + 1);
18498 for (j = 0; j < TREE_VEC_LENGTH (level); ++j)
18499 if (dependent_template_arg_p (TREE_VEC_ELT (level, j)))
18506 /* Returns TRUE if the template TMPL is dependent. */
18509 dependent_template_p (tree tmpl)
18511 if (TREE_CODE (tmpl) == OVERLOAD)
18515 if (dependent_template_p (OVL_FUNCTION (tmpl)))
18517 tmpl = OVL_CHAIN (tmpl);
18522 /* Template template parameters are dependent. */
18523 if (DECL_TEMPLATE_TEMPLATE_PARM_P (tmpl)
18524 || TREE_CODE (tmpl) == TEMPLATE_TEMPLATE_PARM)
18526 /* So are names that have not been looked up. */
18527 if (TREE_CODE (tmpl) == SCOPE_REF
18528 || TREE_CODE (tmpl) == IDENTIFIER_NODE)
18530 /* So are member templates of dependent classes. */
18531 if (TYPE_P (CP_DECL_CONTEXT (tmpl)))
18532 return dependent_type_p (DECL_CONTEXT (tmpl));
18536 /* Returns TRUE if the specialization TMPL<ARGS> is dependent. */
18539 dependent_template_id_p (tree tmpl, tree args)
18541 return (dependent_template_p (tmpl)
18542 || any_dependent_template_arguments_p (args));
18545 /* Returns TRUE if OMP_FOR with DECLV, INITV, CONDV and INCRV vectors
18549 dependent_omp_for_p (tree declv, tree initv, tree condv, tree incrv)
18553 if (!processing_template_decl)
18556 for (i = 0; i < TREE_VEC_LENGTH (declv); i++)
18558 tree decl = TREE_VEC_ELT (declv, i);
18559 tree init = TREE_VEC_ELT (initv, i);
18560 tree cond = TREE_VEC_ELT (condv, i);
18561 tree incr = TREE_VEC_ELT (incrv, i);
18563 if (type_dependent_expression_p (decl))
18566 if (init && type_dependent_expression_p (init))
18569 if (type_dependent_expression_p (cond))
18572 if (COMPARISON_CLASS_P (cond)
18573 && (type_dependent_expression_p (TREE_OPERAND (cond, 0))
18574 || type_dependent_expression_p (TREE_OPERAND (cond, 1))))
18577 if (TREE_CODE (incr) == MODOP_EXPR)
18579 if (type_dependent_expression_p (TREE_OPERAND (incr, 0))
18580 || type_dependent_expression_p (TREE_OPERAND (incr, 2)))
18583 else if (type_dependent_expression_p (incr))
18585 else if (TREE_CODE (incr) == MODIFY_EXPR)
18587 if (type_dependent_expression_p (TREE_OPERAND (incr, 0)))
18589 else if (BINARY_CLASS_P (TREE_OPERAND (incr, 1)))
18591 tree t = TREE_OPERAND (incr, 1);
18592 if (type_dependent_expression_p (TREE_OPERAND (t, 0))
18593 || type_dependent_expression_p (TREE_OPERAND (t, 1)))
18602 /* TYPE is a TYPENAME_TYPE. Returns the ordinary TYPE to which the
18603 TYPENAME_TYPE corresponds. Returns the original TYPENAME_TYPE if
18604 no such TYPE can be found. Note that this function peers inside
18605 uninstantiated templates and therefore should be used only in
18606 extremely limited situations. ONLY_CURRENT_P restricts this
18607 peering to the currently open classes hierarchy (which is required
18608 when comparing types). */
18611 resolve_typename_type (tree type, bool only_current_p)
18620 gcc_assert (TREE_CODE (type) == TYPENAME_TYPE);
18622 scope = TYPE_CONTEXT (type);
18623 /* Usually the non-qualified identifier of a TYPENAME_TYPE is
18624 TYPE_IDENTIFIER (type). But when 'type' is a typedef variant of
18625 a TYPENAME_TYPE node, then TYPE_NAME (type) is set to the TYPE_DECL representing
18626 the typedef. In that case TYPE_IDENTIFIER (type) is not the non-qualified
18627 identifier of the TYPENAME_TYPE anymore.
18628 So by getting the TYPE_IDENTIFIER of the _main declaration_ of the
18629 TYPENAME_TYPE instead, we avoid messing up with a possible
18630 typedef variant case. */
18631 name = TYPE_IDENTIFIER (TYPE_MAIN_VARIANT (type));
18633 /* If the SCOPE is itself a TYPENAME_TYPE, then we need to resolve
18634 it first before we can figure out what NAME refers to. */
18635 if (TREE_CODE (scope) == TYPENAME_TYPE)
18636 scope = resolve_typename_type (scope, only_current_p);
18637 /* If we don't know what SCOPE refers to, then we cannot resolve the
18639 if (TREE_CODE (scope) == TYPENAME_TYPE)
18641 /* If the SCOPE is a template type parameter, we have no way of
18642 resolving the name. */
18643 if (TREE_CODE (scope) == TEMPLATE_TYPE_PARM)
18645 /* If the SCOPE is not the current instantiation, there's no reason
18646 to look inside it. */
18647 if (only_current_p && !currently_open_class (scope))
18649 /* If this is a typedef, we don't want to look inside (c++/11987). */
18650 if (typedef_variant_p (type))
18652 /* If SCOPE isn't the template itself, it will not have a valid
18653 TYPE_FIELDS list. */
18654 if (same_type_p (scope, CLASSTYPE_PRIMARY_TEMPLATE_TYPE (scope)))
18655 /* scope is either the template itself or a compatible instantiation
18656 like X<T>, so look up the name in the original template. */
18657 scope = CLASSTYPE_PRIMARY_TEMPLATE_TYPE (scope);
18659 /* scope is a partial instantiation, so we can't do the lookup or we
18660 will lose the template arguments. */
18662 /* Enter the SCOPE so that name lookup will be resolved as if we
18663 were in the class definition. In particular, SCOPE will no
18664 longer be considered a dependent type. */
18665 pushed_scope = push_scope (scope);
18666 /* Look up the declaration. */
18667 decl = lookup_member (scope, name, /*protect=*/0, /*want_type=*/true);
18669 result = NULL_TREE;
18671 /* For a TYPENAME_TYPE like "typename X::template Y<T>", we want to
18672 find a TEMPLATE_DECL. Otherwise, we want to find a TYPE_DECL. */
18675 else if (TREE_CODE (TYPENAME_TYPE_FULLNAME (type)) == IDENTIFIER_NODE
18676 && TREE_CODE (decl) == TYPE_DECL)
18678 result = TREE_TYPE (decl);
18679 if (result == error_mark_node)
18680 result = NULL_TREE;
18682 else if (TREE_CODE (TYPENAME_TYPE_FULLNAME (type)) == TEMPLATE_ID_EXPR
18683 && DECL_CLASS_TEMPLATE_P (decl))
18687 /* Obtain the template and the arguments. */
18688 tmpl = TREE_OPERAND (TYPENAME_TYPE_FULLNAME (type), 0);
18689 args = TREE_OPERAND (TYPENAME_TYPE_FULLNAME (type), 1);
18690 /* Instantiate the template. */
18691 result = lookup_template_class (tmpl, args, NULL_TREE, NULL_TREE,
18692 /*entering_scope=*/0,
18693 tf_error | tf_user);
18694 if (result == error_mark_node)
18695 result = NULL_TREE;
18698 /* Leave the SCOPE. */
18700 pop_scope (pushed_scope);
18702 /* If we failed to resolve it, return the original typename. */
18706 /* If lookup found a typename type, resolve that too. */
18707 if (TREE_CODE (result) == TYPENAME_TYPE && !TYPENAME_IS_RESOLVING_P (result))
18709 /* Ill-formed programs can cause infinite recursion here, so we
18710 must catch that. */
18711 TYPENAME_IS_RESOLVING_P (type) = 1;
18712 result = resolve_typename_type (result, only_current_p);
18713 TYPENAME_IS_RESOLVING_P (type) = 0;
18716 /* Qualify the resulting type. */
18717 quals = cp_type_quals (type);
18719 result = cp_build_qualified_type (result, cp_type_quals (result) | quals);
18724 /* EXPR is an expression which is not type-dependent. Return a proxy
18725 for EXPR that can be used to compute the types of larger
18726 expressions containing EXPR. */
18729 build_non_dependent_expr (tree expr)
18733 /* Preserve null pointer constants so that the type of things like
18734 "p == 0" where "p" is a pointer can be determined. */
18735 if (null_ptr_cst_p (expr))
18737 /* Preserve OVERLOADs; the functions must be available to resolve
18740 if (TREE_CODE (inner_expr) == STMT_EXPR)
18741 inner_expr = stmt_expr_value_expr (inner_expr);
18742 if (TREE_CODE (inner_expr) == ADDR_EXPR)
18743 inner_expr = TREE_OPERAND (inner_expr, 0);
18744 if (TREE_CODE (inner_expr) == COMPONENT_REF)
18745 inner_expr = TREE_OPERAND (inner_expr, 1);
18746 if (is_overloaded_fn (inner_expr)
18747 || TREE_CODE (inner_expr) == OFFSET_REF)
18749 /* There is no need to return a proxy for a variable. */
18750 if (TREE_CODE (expr) == VAR_DECL)
18752 /* Preserve string constants; conversions from string constants to
18753 "char *" are allowed, even though normally a "const char *"
18754 cannot be used to initialize a "char *". */
18755 if (TREE_CODE (expr) == STRING_CST)
18757 /* Preserve arithmetic constants, as an optimization -- there is no
18758 reason to create a new node. */
18759 if (TREE_CODE (expr) == INTEGER_CST || TREE_CODE (expr) == REAL_CST)
18761 /* Preserve THROW_EXPRs -- all throw-expressions have type "void".
18762 There is at least one place where we want to know that a
18763 particular expression is a throw-expression: when checking a ?:
18764 expression, there are special rules if the second or third
18765 argument is a throw-expression. */
18766 if (TREE_CODE (expr) == THROW_EXPR)
18769 if (TREE_CODE (expr) == COND_EXPR)
18770 return build3 (COND_EXPR,
18772 TREE_OPERAND (expr, 0),
18773 (TREE_OPERAND (expr, 1)
18774 ? build_non_dependent_expr (TREE_OPERAND (expr, 1))
18775 : build_non_dependent_expr (TREE_OPERAND (expr, 0))),
18776 build_non_dependent_expr (TREE_OPERAND (expr, 2)));
18777 if (TREE_CODE (expr) == COMPOUND_EXPR
18778 && !COMPOUND_EXPR_OVERLOADED (expr))
18779 return build2 (COMPOUND_EXPR,
18781 TREE_OPERAND (expr, 0),
18782 build_non_dependent_expr (TREE_OPERAND (expr, 1)));
18784 /* If the type is unknown, it can't really be non-dependent */
18785 gcc_assert (TREE_TYPE (expr) != unknown_type_node);
18787 /* Otherwise, build a NON_DEPENDENT_EXPR.
18789 REFERENCE_TYPEs are not stripped for expressions in templates
18790 because doing so would play havoc with mangling. Consider, for
18793 template <typename T> void f<T& g>() { g(); }
18795 In the body of "f", the expression for "g" will have
18796 REFERENCE_TYPE, even though the standard says that it should
18797 not. The reason is that we must preserve the syntactic form of
18798 the expression so that mangling (say) "f<g>" inside the body of
18799 "f" works out correctly. Therefore, the REFERENCE_TYPE is
18801 return build1 (NON_DEPENDENT_EXPR, non_reference (TREE_TYPE (expr)), expr);
18804 /* ARGS is a vector of expressions as arguments to a function call.
18805 Replace the arguments with equivalent non-dependent expressions.
18806 This modifies ARGS in place. */
18809 make_args_non_dependent (VEC(tree,gc) *args)
18814 FOR_EACH_VEC_ELT (tree, args, ix, arg)
18816 tree newarg = build_non_dependent_expr (arg);
18818 VEC_replace (tree, args, ix, newarg);
18822 /* Returns a type which represents 'auto'. We use a TEMPLATE_TYPE_PARM
18823 with a level one deeper than the actual template parms. */
18828 tree au = cxx_make_type (TEMPLATE_TYPE_PARM);
18829 TYPE_NAME (au) = build_decl (BUILTINS_LOCATION,
18830 TYPE_DECL, get_identifier ("auto"), au);
18831 TYPE_STUB_DECL (au) = TYPE_NAME (au);
18832 TEMPLATE_TYPE_PARM_INDEX (au) = build_template_parm_index
18833 (0, processing_template_decl + 1, processing_template_decl + 1,
18834 0, TYPE_NAME (au), NULL_TREE);
18835 TYPE_CANONICAL (au) = canonical_type_parameter (au);
18836 DECL_ARTIFICIAL (TYPE_NAME (au)) = 1;
18837 SET_DECL_TEMPLATE_PARM_P (TYPE_NAME (au));
18842 /* Given type ARG, return std::initializer_list<ARG>. */
18847 tree std_init_list = namespace_binding
18848 (get_identifier ("initializer_list"), std_node);
18850 if (!std_init_list || !DECL_CLASS_TEMPLATE_P (std_init_list))
18852 error ("deducing from brace-enclosed initializer list requires "
18853 "#include <initializer_list>");
18854 return error_mark_node;
18856 argvec = make_tree_vec (1);
18857 TREE_VEC_ELT (argvec, 0) = arg;
18858 return lookup_template_class (std_init_list, argvec, NULL_TREE,
18859 NULL_TREE, 0, tf_warning_or_error);
18862 /* Replace auto in TYPE with std::initializer_list<auto>. */
18865 listify_autos (tree type, tree auto_node)
18867 tree init_auto = listify (auto_node);
18868 tree argvec = make_tree_vec (1);
18869 TREE_VEC_ELT (argvec, 0) = init_auto;
18870 if (processing_template_decl)
18871 argvec = add_to_template_args (current_template_args (), argvec);
18872 return tsubst (type, argvec, tf_warning_or_error, NULL_TREE);
18875 /* walk_tree helper for do_auto_deduction. */
18878 contains_auto_r (tree *tp, int *walk_subtrees ATTRIBUTE_UNUSED,
18881 /* Is this a variable with the type we're looking for? */
18883 && TREE_TYPE (*tp) == type)
18889 /* Replace occurrences of 'auto' in TYPE with the appropriate type deduced
18890 from INIT. AUTO_NODE is the TEMPLATE_TYPE_PARM used for 'auto' in TYPE. */
18893 do_auto_deduction (tree type, tree init, tree auto_node)
18895 tree parms, tparms, targs;
18900 /* The name of the object being declared shall not appear in the
18901 initializer expression. */
18902 decl = cp_walk_tree_without_duplicates (&init, contains_auto_r, type);
18905 error ("variable %q#D with %<auto%> type used in its own "
18906 "initializer", decl);
18907 return error_mark_node;
18910 /* [dcl.spec.auto]: Obtain P from T by replacing the occurrences of auto
18911 with either a new invented type template parameter U or, if the
18912 initializer is a braced-init-list (8.5.4), with
18913 std::initializer_list<U>. */
18914 if (BRACE_ENCLOSED_INITIALIZER_P (init))
18915 type = listify_autos (type, auto_node);
18917 init = resolve_nondeduced_context (init);
18919 parms = build_tree_list (NULL_TREE, type);
18921 tparms = make_tree_vec (1);
18922 targs = make_tree_vec (1);
18923 TREE_VEC_ELT (tparms, 0)
18924 = build_tree_list (NULL_TREE, TYPE_NAME (auto_node));
18925 val = type_unification_real (tparms, targs, parms, args, 1, 0,
18926 DEDUCE_CALL, LOOKUP_NORMAL);
18929 if (type && type != error_mark_node)
18930 /* If type is error_mark_node a diagnostic must have been
18931 emitted by now. Also, having a mention to '<type error>'
18932 in the diagnostic is not really useful to the user. */
18933 error ("unable to deduce %qT from %qE", type, init);
18934 return error_mark_node;
18937 /* If the list of declarators contains more than one declarator, the type
18938 of each declared variable is determined as described above. If the
18939 type deduced for the template parameter U is not the same in each
18940 deduction, the program is ill-formed. */
18941 if (TREE_TYPE (auto_node)
18942 && !same_type_p (TREE_TYPE (auto_node), TREE_VEC_ELT (targs, 0)))
18944 error ("inconsistent deduction for %qT: %qT and then %qT",
18945 auto_node, TREE_TYPE (auto_node), TREE_VEC_ELT (targs, 0));
18946 return error_mark_node;
18948 TREE_TYPE (auto_node) = TREE_VEC_ELT (targs, 0);
18950 if (processing_template_decl)
18951 targs = add_to_template_args (current_template_args (), targs);
18952 return tsubst (type, targs, tf_warning_or_error, NULL_TREE);
18955 /* Substitutes LATE_RETURN_TYPE for 'auto' in TYPE and returns the
18959 splice_late_return_type (tree type, tree late_return_type)
18963 if (late_return_type == NULL_TREE)
18965 argvec = make_tree_vec (1);
18966 TREE_VEC_ELT (argvec, 0) = late_return_type;
18967 if (processing_template_decl)
18968 argvec = add_to_template_args (current_template_args (), argvec);
18969 return tsubst (type, argvec, tf_warning_or_error, NULL_TREE);
18972 /* Returns true iff TYPE is a TEMPLATE_TYPE_PARM representing 'auto'. */
18975 is_auto (const_tree type)
18977 if (TREE_CODE (type) == TEMPLATE_TYPE_PARM
18978 && TYPE_IDENTIFIER (type) == get_identifier ("auto"))
18984 /* Returns true iff TYPE contains a use of 'auto'. Since auto can only
18985 appear as a type-specifier for the declaration in question, we don't
18986 have to look through the whole type. */
18989 type_uses_auto (tree type)
18991 enum tree_code code;
18992 if (is_auto (type))
18995 code = TREE_CODE (type);
18997 if (code == POINTER_TYPE || code == REFERENCE_TYPE
18998 || code == OFFSET_TYPE || code == FUNCTION_TYPE
18999 || code == METHOD_TYPE || code == ARRAY_TYPE)
19000 return type_uses_auto (TREE_TYPE (type));
19002 if (TYPE_PTRMEMFUNC_P (type))
19003 return type_uses_auto (TREE_TYPE (TREE_TYPE
19004 (TYPE_PTRMEMFUNC_FN_TYPE (type))));
19009 /* For a given template T, return the vector of typedefs referenced
19010 in T for which access check is needed at T instantiation time.
19011 T is either a FUNCTION_DECL or a RECORD_TYPE.
19012 Those typedefs were added to T by the function
19013 append_type_to_template_for_access_check. */
19015 VEC(qualified_typedef_usage_t,gc)*
19016 get_types_needing_access_check (tree t)
19019 VEC(qualified_typedef_usage_t,gc) *result = NULL;
19021 if (!t || t == error_mark_node)
19024 if (!(ti = get_template_info (t)))
19027 if (CLASS_TYPE_P (t)
19028 || TREE_CODE (t) == FUNCTION_DECL)
19030 if (!TI_TEMPLATE (ti))
19033 result = TI_TYPEDEFS_NEEDING_ACCESS_CHECKING (ti);
19039 /* Append the typedef TYPE_DECL used in template T to a list of typedefs
19040 tied to T. That list of typedefs will be access checked at
19041 T instantiation time.
19042 T is either a FUNCTION_DECL or a RECORD_TYPE.
19043 TYPE_DECL is a TYPE_DECL node representing a typedef.
19044 SCOPE is the scope through which TYPE_DECL is accessed.
19045 LOCATION is the location of the usage point of TYPE_DECL.
19047 This function is a subroutine of
19048 append_type_to_template_for_access_check. */
19051 append_type_to_template_for_access_check_1 (tree t,
19054 location_t location)
19056 qualified_typedef_usage_t typedef_usage;
19059 if (!t || t == error_mark_node)
19062 gcc_assert ((TREE_CODE (t) == FUNCTION_DECL
19063 || CLASS_TYPE_P (t))
19065 && TREE_CODE (type_decl) == TYPE_DECL
19068 if (!(ti = get_template_info (t)))
19071 gcc_assert (TI_TEMPLATE (ti));
19073 typedef_usage.typedef_decl = type_decl;
19074 typedef_usage.context = scope;
19075 typedef_usage.locus = location;
19077 VEC_safe_push (qualified_typedef_usage_t, gc,
19078 TI_TYPEDEFS_NEEDING_ACCESS_CHECKING (ti),
19082 /* Append TYPE_DECL to the template TEMPL.
19083 TEMPL is either a class type, a FUNCTION_DECL or a a TEMPLATE_DECL.
19084 At TEMPL instanciation time, TYPE_DECL will be checked to see
19085 if it can be accessed through SCOPE.
19086 LOCATION is the location of the usage point of TYPE_DECL.
19088 e.g. consider the following code snippet:
19095 template<class U> struct S
19097 C::myint mi; // <-- usage point of the typedef C::myint
19102 At S<char> instantiation time, we need to check the access of C::myint
19103 In other words, we need to check the access of the myint typedef through
19104 the C scope. For that purpose, this function will add the myint typedef
19105 and the scope C through which its being accessed to a list of typedefs
19106 tied to the template S. That list will be walked at template instantiation
19107 time and access check performed on each typedefs it contains.
19108 Note that this particular code snippet should yield an error because
19109 myint is private to C. */
19112 append_type_to_template_for_access_check (tree templ,
19115 location_t location)
19117 qualified_typedef_usage_t *iter;
19120 gcc_assert (type_decl && (TREE_CODE (type_decl) == TYPE_DECL));
19122 /* Make sure we don't append the type to the template twice. */
19123 FOR_EACH_VEC_ELT (qualified_typedef_usage_t,
19124 get_types_needing_access_check (templ),
19126 if (iter->typedef_decl == type_decl && scope == iter->context)
19129 append_type_to_template_for_access_check_1 (templ, type_decl,
19133 /* Set up the hash tables for template instantiations. */
19136 init_template_processing (void)
19138 decl_specializations = htab_create_ggc (37,
19139 hash_specialization,
19140 eq_specializations,
19142 type_specializations = htab_create_ggc (37,
19143 hash_specialization,
19144 eq_specializations,
19148 /* Print stats about the template hash tables for -fstats. */
19151 print_template_statistics (void)
19153 fprintf (stderr, "decl_specializations: size %ld, %ld elements, "
19154 "%f collisions\n", (long) htab_size (decl_specializations),
19155 (long) htab_elements (decl_specializations),
19156 htab_collisions (decl_specializations));
19157 fprintf (stderr, "type_specializations: size %ld, %ld elements, "
19158 "%f collisions\n", (long) htab_size (type_specializations),
19159 (long) htab_elements (type_specializations),
19160 htab_collisions (type_specializations));
19163 #include "gt-cp-pt.h"